35161
2013
2013
eng
3
18
16
2
43
preprint
Elsevier
Amsterdam
CTA Consortium
1
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Introducing the CTA concept
The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project.
Astroparticle physics
10.1016/j.astropartphys.2013.01.007
0927-6505
1873-2852
wos:2011-2013
WOS:000318126800002
Martinez, M (reprint author), Inst Fis Altes Energies, Barcelona, Spain., martinez@ifae.es
B. S. Acharya
M. Actis
T. Aghajani
G. Agnetta
J. Aguilar
Felix A. Aharonian
M. Ajello
A. G. Akhperjanian
M. Alcubierre
J. Aleksic
R. Alfaro
E. Aliu
A. J. Allafort
D. Allan
I. Allekotte
E. Amato
J. Anderson
Ekrem Oǧuzhan Angüner
L. A. Antonelli
P. Antoranz
A. Aravantinos
T. Arlen
T. Armstrong
H. Arnaldi
L. Arrabito
K. Asano
T. Ashton
H. G. Asorey
Y. Awane
H. Baba
A. Babic
N. Baby
J. Baehr
A. Bais
C. Baixeras
S. Bajtlik
M. Balbo
D. Balis
C. Balkowski
A. Bamba
R. Bandiera
A. Barber
C. Barbier
M. Barcelo
Anna Barnacka
Jürgen Barnstedt
U. Barres de Almeida
J. A. Barrio
A. Basili
S. Basso
D. Bastieri
C. Bauer
Anton N. Baushev
J. Becerra Gonzalez
Yvonne Becherini
K. C. Bechtol
J. Becker Tjus
Volker Beckmann
W. Bednarek
B. Behera
M. Belluso
W. Benbow
J. Berdugo
K. Berger
F. Bernard
T. Bernardino
K. Bernlöhr
N. Bhat
S. Bhattacharyya
C. Bigongiari
A. Biland
S. Billotta
T. Bird
E. Birsin
E. Bissaldi
Jonathan Biteau
M. Bitossi
S. Blake
O. Blanch Bigas
P. Blasi
A. A. Bobkov
V. Boccone
Markus Boettcher
L. Bogacz
J. Bogart
M. Bogdan
Catherine Boisson
J. Boix Gargallo
J. Bolmont
G. Bonanno
A. Bonardi
T. Bonev
P. Bonifacio
G. Bonnoli
Pol Bordas
A. W. Borgland
Janett Borkowski
R. Bose
O. Botner
A. Bottani
L. Bouchet
M. Bourgeat
C. Boutonnet
A. Bouvier
S. Brau-Nogue
I. Braun
T. Bretz
M. S. Briggs
T. Bringmann
P. Brook
Pierre Brun
L. Brunetti
T. Buanes
J. H. Buckley
R. Buehler
V. Bugaev
A. Bulgarelli
Tomasz Bulik
G. Busetto
S. Buson
K. Byrum
M. Cailles
R. A. Cameron
J. Camprecios
R. Canestrari
S. Cantu
M. Capalbi
P. A. Caraveo
E. Carmona
A. Carosi
John Carr
P. H. Carton
Sabrina Casanova
M. Casiraghi
O. Catalano
S. Cavazzani
S. Cazaux
M. Cerruti
E. Chabanne
Paula M. Chadwick
C. Champion
Andrew Chen
J. Chiang
L. Chiappetti
M. Chikawa
V. R. Chitnis
F. Chollet
J. Chudoba
M. Cieslar
A. N. Cillis
J. Cohen-Tanugi
Sergio Colafrancesco
P. Colin
J. Calome
S. Colonges
M. Compin
P. Conconi
V. Conforti
V. Connaughton
Jan Conrad
J. L. Contreras
P. Coppi
P. Corona
D. Corti
J. Cortina
L. Cossio
H. Costantini
G. Cotter
B. Courty
S. Couturier
S. Covino
G. Crimi
S. J. Criswell
J. Croston
G. Cusumano
M. Dafonseca
O. Dale
M. Daniel
J. Darling
I. Davids
F. Dazzi
A. De Angelis
V. De Caprio
F. De Frondat
E. M. de Gouveia Dal Pino
I. de la Calle
G. A. De La Vega
R. de los Reyes Lopez
B. De Lotto
A. De Luca
J. R. T. de Mello Neto
M. de Naurois
Y. de Oliveira
E. de Ona Wilhelmi
V. de Souza
G. Decerprit
G. Decock
C. Deil
E. Delagnes
G. Deleglise
C. Delgado
D. Della Volpe
P. Demange
G. Depaola
A. Dettlaff
A. Di Paola
F. Di Pierro
C. Diaz
J. Dick
R. Dickherber
H. Dickinson
V. Diez-Blanco
S. Digel
D. Dimitrov
G. Disset
A. Djannati-Ataï
M. Doert
M. Dohmke
W. Domainko
Dijana Dominis Prester
A. Donat
D. Dorner
M. Doro
J-L. Dournaux
G. Drake
D. Dravins
L. Drury
F. Dubois
R. Dubois
G. Dubus
C. Dufour
D. Dumas
J. Dumm
D. Durand
J. Dyks
M. Dyrda
J. Ebr
E. Edy
Kathrin Egberts
P. Eger
S. Einecke
C. Eleftheriadis
S. Elles
D. Emmanoulopoulos
D. Engelhaupt
R. Enomoto
J-P Ernenwein
M. Errando
A. Etchegoyen
P. Evans
A. Falcone
D. Fantinel
K. Farakos
C. Farnier
G. Fasola
B. Favill
E. Fede
S. Federici
S. Fegan
F. Feinstein
D. Ferenc
P. Ferrando
M. Fesquet
A. Fiasson
E. Fillin-Martino
D. Fink
C. Finley
J. P. Finley
M. Fiorini
R. Firpo Curcoll
H. Flores
D. Florin
W. Focke
C. Foehr
E. Fokitis
L. Font
G. Fontaine
M. Fornasa
A. Foerster
L. Fortson
N. Fouque
A. Franckowiak
C. Fransson
G. Fraser
R. Frei
I. F. M. Albuquerque
L. Fresnillo
C. Fruck
Y. Fujita
Y. Fukazawa
Y. Fukui
S. Funk
W. Gaebele
S. Gabici
R. Gabriele
A. Gadola
N. Galante
D. Gall
Y. Gallant
J. Gamez-Garcia
B. Garcia
R. Garcia Lopez
D. Gardiol
D. Garrido
L. Garrido
D. Gascon
M. Gaug
J. Gaweda
L. Gebremedhin
N. Geffroy
L. Gerard
A. Ghedina
M. Ghigo
E. Giannakaki
F. Gianotti
S. Giarrusso
G. Giavitto
B. Giebels
V. Gika
P. Giommi
N. Girard
E. Giro
A. Giuliani
T. Glanzman
J. -F. Glicenstein
N. Godinovic
V. Golev
M. Gomez Berisso
J. Gomez-Ortega
M. M. Gonzalez
A. Gonzalez
F. Gonzalez
A. Gonzalez Munoz
K. S. Gothe
M. Gougerot
R. Graciani
P. Grandi
F. Granena
J. Granot
G. Grasseau
R. Gredig
A. Green
T. Greenshaw
T. Gregoire
O. Grimm
J. Grube
M. Grudzinska
V. Gruev
S. Gruenewald
J. Grygorczuk
V. Guarino
S. Gunji
G. Gyuk
D. Hadasch
R. Hagiwara
J. Hahn
N. Hakansson
A. Hallgren
N. Hamer Heras
S. Hara
M. J. Hardcastle
J. Harris
T. Hassan
K. Hatanaka
T. Haubold
A. Haupt
T. Hayakawa
M. Hayashida
R. Heller
F. Henault
G. Henri
G. Hermann
R. Hermel
A. Herrero
N. Hidaka
J. Hinton
D. Hoffmann
W. Hofmann
P. Hofverberg
J. Holder
D. Horns
D. Horville
J. Houles
M. Hrabovsky
D. Hrupec
H. Huan
B. Huber
J. -M. Huet
G. Hughes
T. B. Humensky
J. Huovelin
A. Ibarra
J. M. Illa
D. Impiombato
S. Incorvaia
S. Inoue
Y. Inoue
K. Ioka
E. Ismailova
C. Jablonski
A. Jacholkowska
M. Jamrozy
M. Janiak
P. Jean
C. Jeanney
J. J. Jimenez
T. Jogler
T. Johnson
L. Journet
C. Juffroy
I. Jung
P. Kaaret
S. Kabuki
M. Kagaya
J. Kakuwa
C. Kalkuhl
R. Kankanyan
A. Karastergiou
K. Kaercher
M. Karczewski
S. Karkar
Aci. Kasperek
D. Kastana
H. Katagiri
J. Kataoka
K. Katarzynski
U. Katz
N. Kawanaka
B. Kellner-Leidel
H. Kelly
E. Kendziorra
B. Khelifi
D. B. Kieda
T. Kifune
T. Kihm
T. Kishimoto
K. Kitamoto
W. Kluzniak
C. Knapic
J. w Knapp
J. Knoedlseder
F. Koeck
J. Kocot
K. Kodani
J. -H. Koehne
K. Kohri
K. Kokkotas
D. Kolitzus
N. Komin
I. Kominis
Y. Konno
H. Koeppel
P. Korohoda
K. Kosack
G. Koss
R. Kossakowski
P. Kostka
R. Koul
G. Kowal
S. Koyama
J. Koziol
T. Kraehenbuehl
J. Krause
H. Krawzcynski
F. Krennrich
A. Krepps
A. Kretzschmann
R. Krobot
P. Krueger
H. Kubo
V. A. Kudryavtsev
J. Kushida
A. Kuznetsov
A. La Barbera
N. La Palombara
V. La Parola
G. La Rosa
K. Lacombe
G. Lamanna
J. Lande
D. Languignon
J. Lapington
P. Laporte
C. Lavalley
T. Le Flour
A. Le Padellec
S. -H. Lee
W. H. Lee
M. A. Leigui de Oliveira
D. Lelas
J. -P. Lenain
D. J. Leopold
T. Lerch
L. Lessio
B. Lieunard
E. Lindfors
A. Liolios
A. Lipniacka
H. Lockart
T. Lohse
S. Lombardi
A. Lopatin
M. Lopez
R. Lopez-Coto
A. Lopez-Oramas
A. Lorca
E. Lorenz
P. Lubinski
F. Lucarelli
H. Luedecke
J. Ludwin
P. L. Luque-Escamilla
W. Lustermann
O. Luz
E. Lyard
M. C. Maccarone
T. J. Maccarone
G. M. Madejski
A. Madhavan
M. Mahabir
G. Maier
P. Majumdar
G. Malaguti
S. Maltezos
A. Manalaysay
A. Mancilla
D. Mandat
G. Maneva
A. Mangano
P. Manigot
K. Mannheim
I. Manthos
N. Maragos
A. Marcowith
M. Mariotti
M. Marisaldi
S. Markoff
A. Marszalek
C. Martens
J. Marti
J-M. Martin
P. Martin
G. Martinez
F. Martinez
M. Martinez
A. Masserot
A. Mastichiadis
A. Mathieu
H. Matsumoto
F. Mattana
S. Mattiazzo
G. Maurin
S. Maxfield
J. Maya
D. Mazin
L. Mc Comb
N. McCubbin
I. McHardy
R. McKay
C. Medina
C. Melioli
D. Melkumyan
S. Mereghetti
P. Mertsch
M. Meucci
J. Michalowski
P. Micolon
A. Mihailidis
T. Mineo
M. Minuti
N. Mirabal
F. Mirabel
J. M. Miranda
R. Mirzoyan
T. Mizuno
B. Moal
R. Moderski
I. Mognet
E. Molinari
M. Molinaro
T. Montaruli
I. Monteiro
P. Moore
A. Moralejo Olaizola
M. Mordalska
C. Morello
K. Mori
F. Mottez
Y. Moudden
E. Moulin
I. Mrusek
R. Mukherjee
P. Munar-Adrover
H. Muraishi
K. Murase
A. Murphy
S. Nagataki
T. Naito
D. Nakajima
T. Nakamori
K. Nakayama
C. L. Naumann
D. Naumann
M. Naumann-Godo
P. Nayman
D. Nedbal
D. Neise
L. Nellen
V. Neustroev
N. Neyroud
L. Nicastro
J. Nicolau-Kuklinski
A. Niedzwiecki
J. Niemiec
D. Nieto
A. Nikolaidis
K. Nishijima
S. Nolan
R. Northrop
D. Nosek
N. Nowak
A. Nozato
P. O'Brien
Y. Ohira
M. Ohishi
S. Ohm
H. Ohoka
T. Okuda
A. Okumura
J. -F. Olive
R. A. Ong
R. Orito
M. Orr
J. Osborne
M. Ostrowski
L. A. Otero
N. Otte
E. Ovcharov
I. Oya
A. Ozieblo
L. Padilla
S. Paiano
D. Paillot
A. Paizis
S. Palanque
M. Palatka
J. Pallota
K. Panagiotidis
J. -L. Panazol
D. Paneque
M. Panter
R. Paoletti
Alexandros Papayannis
G. Papyan
J. M. Paredes
G. Pareschi
G. Parks
J. -M. Parraud
D. Parsons
M. Paz Arribas
M. Pech
G. Pedaletti
V. Pelassa
D. Pelat
M. D. C. Perez
M. Persic
P-O Petrucci
B. Peyaud
A. Pichel
S. Pita
F. Pizzolato
L. Platos
R. Platzer
L. Pogosyan
M. Pohl
G. Pojmanski
J. D. Ponz
W. Potter
J. Poutanen
E. Prandini
J. Prast
R. Preece
F. Profeti
H. Prokoph
M. Prouza
M. Proyetti
I. Puerto-Gimenez
G. Puehlhofer
I. Puljak
M. Punch
R. Pyziol
E. J. Quel
J. Quinn
A. Quirrenbach
E. Racero
P. J. Rajda
P. Ramon
R. Rando
R. C. Rannot
M. Rataj
M. Raue
P. Reardon
O. Reimann
A. Reimer
O. Reimer
K. Reitberger
M. Renaud
S. Renner
B. Reville
W. Rhode
M. Ribo
M. Ribordy
M. G. Richer
J. Rico
J. Ridky
F. Rieger
P. Ringegni
J. Ripken
P. R. Ristori
A. Riviere
S. Rivoire
L. Rob
U. Roeser
R. Rohlfs
G. Rojas
P. Romano
W. Romaszkan
G. E. Romero
S. Rosen
S. Rosier Lees
D. Ross
G. Rouaix
J. Rousselle
S. Rousselle
A. C. Rovero
F. Roy
S. Royer
B. Rudak
C. Rulten
M. Rupinski
F. Russo
F. Ryde
B. Sacco
E. O. Saemann
A. Saggion
V. Safiakian
K. Saito
T. Saito
Y. Saito
N. Sakaki
R. Sakonaka
A. Salini
F. Sanchez
M. Sanchez-Conde
A. Sandoval
H. Sandaker
E. Sant'Ambrogio
A. Santangelo
E. M. Santos
A. Sanuy
L. Sapozhnikov
S. Sarkar
N. Sartore
H. Sasaki
K. Satalecka
M. Sawada
V. Scalzotto
V. Scapin
M. Scarcioffolo
J. Schafer
T. Schanz
S. Schlenstedt
R. Schlickeiser
T. Schmidt
J. Schmoll
P. Schovanek
M. Schroedter
C. Schultz
J. Schultze
A. Schulz
K. Schure
T. Schwab
U. Schwanke
J. Schwarz
S. Schwarzburg
T. Schweizer
S. Schwemmer
A. Segreto
J. -H. Seiradakis
G. H. Sembroski
K. Seweryn
M. Sharma
M. Shayduk
R. C. Shellard
J. Shi
T. Shibata
A. Shibuya
E. Shum
L. Sidoli
M. Sidz
J. Sieiro
M. Sikora
J. Silk
A. Sillanpaa
B. B. Singh
J. Sitarek
C. Skole
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A. Smith
D. Smith
J. Smith
N. Smith
D. Sobczynska
H. Sol
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M. Sowinski
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D. Spiga
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V. Stamatescu
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R. Starling
L. Stawarz
R. Steenkamp
Christian Stegmann
S. Steiner
N. Stergioulas
R. Sternberger
M. Sterzel
F. Stinzing
M. Stodulski
U. Straumann
E. Strazzeri
L. Stringhetti
A. Suarez
M. Suchenek
R. Sugawara
K. -H. Sulanke
S. Sun
A. D. Supanitsky
T. Suric
P. Sutcliffe
J. Sykes
M. Szanecki
T. Szepieniec
A. Szostek
G. Tagliaferri
H. Tajima
H. Takahashi
K. Takahashi
L. Takalo
H. Takami
C. Talbot
J. Tammi
M. Tanaka
S. Tanaka
J. Tasan
M. Tavani
J. -P. Tavernet
L. A. Tejedor
Igor O. Telezhinsky
P. Temnikov
C. Tenzer
Y. Terada
R. Terrier
M. Teshima
V. Testa
D. Tezier
D. Thuermann
L. Tibaldo
O. Tibolla
A. Tiengo
M. Tluczykont
C. J. Todero Peixoto
F. Tokanai
M. Tokarz
K. Toma
K. Torii
M. Tornikoski
D. F. Torres
M. Torres
G. Tosti
T. Totani
C. Toussenel
G. Tovmassian
P. Travnicek
M. Trifoglio
I. Troyano
K. Tsinganos
H. Ueno
K. Umehara
S. S. Upadhya
T. Usher
M. Uslenghi
J. F. Valdes-Galicia
P. Vallania
G. Vallejo
W. van Driel
C. van Eldik
J. Vandenbrouke
J. Vanderwalt
H. Vankov
G. Vasileiadis
V. Vassiliev
D. Veberic
I. Vegas
S. Vercellone
S. Vergani
C. Veyssiere
J. P. Vialle
A. Viana
M. Videla
P. Vincent
S. Vincent
J. Vink
N. Vlahakis
L. Vlahos
P. Vogler
A. Vollhardt
H. P. von Gunten
S. Vorobiov
C. Vuerli
V. Waegebaert
R. Wagner
R. G. Wagner
S. Wagner
S. P. Wakely
R. Walter
T. Walther
K. Warda
R. Warwick
P. Wawer
R. Wawrzaszek
N. Webb
P. Wegner
A. Weinstein
Q. Weitzel
R. Welsing
M. Werner
H. Wetteskind
R. White
A. Wierzcholska
S. Wiesand
M. Wilkinson
D. A. Williams
R. Willingale
K. Winiarski
R. Wischnewski
L. Wisniewski
M. Wood
A. Woernlein
Q. Xiong
K. K. Yadav
H. Yamamoto
T. Yamamoto
R. Yamazaki
S. Yanagita
J. M. Yebras
D. Yelos
A. Yoshida
T. Yoshida
T. Yoshikoshi
V. Zabalza
M. Zacharias
A. Zajczyk
R. Zanin
A. Zdziarski
Alraune Zech
A. Zhao
X. Zhou
K. Zietara
J. Ziolkowski
P. Ziolkowski
V. Zitelli
C. Zurbach
P. Zychowski
eng
uncontrolled
TeV gamma-ray astronomy
eng
uncontrolled
Air showers
eng
uncontrolled
Cherenkov Telescopes
Institut für Physik und Astronomie
Referiert
36450
2011
2011
eng
193
316
124
3
32
article
Springer
Dordrecht
CTA Consortium
1
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Design concepts for the Cherenkov Telescope Array CTA an advanced facility for ground-based high-energy gamma-ray astronomy
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
Experimental astronomy : an international journal on astronomical instrumentation and data analysis
10.1007/s10686-011-9247-0
0922-6435
1572-9508
wos:2011-2013
WOS:000300769700001
Hofmann, W (reprint author), Heidelberg Univ, CTA Project Off, D-69117 Heidelberg, Germany., Werner.Hofmann@mpi-hd.mpg.de; martinez@ifae.es
Ministerio de Ciencia, Tecnologia e Innovacion Productiva (MinCyT);
Comision Nacional de Energia Atomica (CNEA); Consejo Nacional de
Investigaciones Cientificas y Tecnicas (CONICET) Argentina; State
Committee of Science of Armenia; Ministry for Research, France;
CNRS-INSU, France; CNRS-IN2P3, France; CEA, France; Max Planck Society,
Germany; BMBF, Germany; DESY, Germany; Helmholtz Association, Germany;
MIUR, Italy; Netherlands Research School for Astronomy (NOVA);
Netherlands Organization for Scientific Research (NWO); Ministry of
Science and Higher Education, Poland; National Centre for Research and
Development, Poland; MICINN; CPAN, Spain; MultiDark Consolider-Ingenio
programme, Spain; Swedish Research Council, Sweden; Royal Swedish
Academy of Sciences, Sweden; Swiss National Science Foundation (SNSF),
Switzerland; Leverhulme Trust, UK; Royal Society, UK; Science and
Technologies Facilities Council, UK; Durham University, UK; National
Science Foundation; Department of Energy; Argonne National Laboratory;
University of California; University of Chicago; Iowa State University;
Institute for Nuclear and Particle Astrophysics (INPAC-MRPI); Washington
University McDonnell Center for the Space Sciences, USA
M. Actis
G. Agnetta
Felix A. Aharonian
A. G. Akhperjanian
J. Aleksic
E. Aliu
D. Allan
I. Allekotte
F. Antico
L. A. Antonelli
P. Antoranz
A. Aravantinos
T. Arlen
H. Arnaldi
S. Artmann
K. Asano
H. G. Asorey
J. Baehr
A. Bais
C. Baixeras
S. Bajtlik
D. Balis
A. Bamba
C. Barbier
M. Barcelo
Anna Barnacka
Jürgen Barnstedt
U. Barres de Almeida
J. A. Barrio
S. Basso
D. Bastieri
C. Bauer
J. Becerra Gonzalez
Yvonne Becherini
K. C. Bechtol
J. Becker
Volker Beckmann
W. Bednarek
B. Behera
M. Beilicke
M. Belluso
M. Benallou
W. Benbow
J. Berdugo
K. Berger
T. Bernardino
K. Bernlöhr
A. Biland
S. Billotta
T. Bird
E. Birsin
E. Bissaldi
S. Blake
O. Blanch Bigas
A. A. Bobkov
L. Bogacz
M. Bogdan
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B. De Lotto
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L. Guglielmi
F. Guilloux
S. Gunji
G. Gyuk
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D. Haefner
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J. Hahn
A. Hallgren
S. Hara
M. J. Hardcastle
T. Hassan
T. Haubold
M. Hauser
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R. Heller
G. Henri
G. Hermann
A. Herrero
James Anthony Hinton
D. Hoffmann
W. Hofmann
P. Hofverberg
D. Horns
D. Hrupec
H. Huan
B. Huber
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M. C. Maccarone
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H. Matsumoto
S. Mattiazzo
D. Mazin
T. J. L. McComb
N. McCubbin
I. McHardy
C. Medina
D. Melkumyan
A. Mendes
P. Mertsch
M. Meucci
J. Michalowski
P. Micolon
T. Mineo
N. Mirabal
F. Mirabel
J. M. Miranda
R. Mirzoyan
T. Mizuno
B. Moal
R. Moderski
E. Molinari
I. Monteiro
A. Moralejo
C. Morello
K. Mori
G. Motta
F. Mottez
E. Moulin
R. Mukherjee
P. Munar
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A. Stj. Murphy
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T. Nakamori
K. Nakayama
C. L. Naumann
D. Naumann
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D. Nedbal
A. Niedzwiecki
J. Niemiec
A. Nikolaidis
K. Nishijima
S. J. Nolan
N. Nowak
P. T. O'Brien
I. Ochoa
Y. Ohira
M. Ohishi
H. Ohka
A. Okumura
C. Olivetto
R. A. Ong
R. Orito
M. Orr
J. P. Osborne
M. Ostrowski
L. Otero
A. N. Otte
E. Ovcharov
I. Oya
A. Ozieblo
S. Paiano
J. Pallota
J. L. Panazol
D. Paneque
M. Panter
R. Paoletti
G. Papyan
J. M. Paredes
G. Pareschi
R. D. Parsons
M. Paz Arribas
G. Pedaletti
A. Pepato
M. Persic
P. O. Petrucci
B. Peyaud
W. Piechocki
S. Pita
G. Pivato
L. Platos
R. Platzer
L. Pogosyan
Martin Pohl
G. Pojmanski
J. D. Ponz
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H. Prokoph
G. Puehlhofer
M. Punch
E. Quel
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P. Rajda
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C. Reimann
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R. Steenkamp
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N. Stergioulas
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U. Straumann
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A. Szostek
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K. Takahashi
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M. Tavani
J. -P. Tavernet
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L. A. Tejedor
Igor O. Telezhinsky
P. Temnikov
C. Tenzer
Y. Terada
R. Terrier
M. Teshima
V. Testa
L. Tibaldo
O. Tibolla
M. Tluczykont
C. J. Todero Peixoto
F. Tokanai
M. Tokarz
K. Toma
D. F. Torres
G. Tosti
T. Totani
F. Toussenel
P. Vallania
G. Vallejo
J. van der Walt
C. van Eldik
J. Vandenbroucke
H. Vankov
G. Vasileiadis
V. V. Vassiliev
I. Vegas
L. Venter
S. Vercellone
C. Veyssiere
J. P. Vialle
M. Videla
P. Vincent
J. Vink
N. Vlahakis
L. Vlahos
P. Vogler
A. Vollhardt
F. Volpe
H. P. Von Gunten
S. Vorobiov
S. Wagner
R. M. Wagner
B. Wagner
S. P. Wakely
P. Walter
R. Walter
R. Warwick
P. Wawer
R. Wawrzaszek
N. Webb
P. Wegner
A. Weinstein
Q. Weitzel
R. Welsing
H. Wetteskind
R. White
A. Wierzcholska
M. I. Wilkinson
D. A. Williams
M. Winde
R. Wischnewski
L. Wisniewski
A. Wolczko
M. Wood
Q. Xiong
T. Yamamoto
K. Yamaoka
R. Yamazaki
S. Yanagita
B. Yoffo
M. Yonetani
A. Yoshida
T. Yoshida
T. Yoshikoshi
V. Zabalza
A. Zagdanski
A. Zajczyk
A. Zdziarski
Alraune Zech
K. Zietara
P. Ziolkowski
V. Zitelli
P. Zychowski
eng
uncontrolled
Ground based gamma ray astronomy
eng
uncontrolled
Next generation Cherenkov telescopes
eng
uncontrolled
Design concepts
Institut für Physik und Astronomie
Referiert
36122
2012
2012
eng
18
2
746
article
IOP Publ. Ltd.
Bristol
HESS Collaboration, MAGIC Collaboration, VERITAS Collaboration
1
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The 2010 very high energy gamma-ray flare and 10 years ofmulti-wavelength oservations of M 87
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/746/2/151
0004-637X
wos:2011-2013
151
WOS:000300406300037
Abramowski, A (reprint author), Univ Hamburg, Inst Expt Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany., martin.raue@desy.de; stawarz@astro.isas.jaxa.jp; colin@mppmu.mpg.de; mazin@ifae.es; beilicke@physics.wustl.edu; cmhui@physics.utah.edu
Namibian authorities; German Ministry for Education and Research (BMBF);
Max Planck Society; French Ministry for Research; CNRS-IN2P3; CNRS; U.K.
Science and Technology Facilities Council (STFC); IPNP of the Charles
University; Polish Ministry of Science and Higher Education; South
African Department of Science and Technology; National Research
Foundation; University of Namibia; German BMBF; German MPG; Italian
INFN; Swiss National Fund SNF; Spanish MICINN; Bulgarian NSF
[CSD2007-00042, CSD2009-00064, DO02-353]; Academy of Finland [127740];
YIP of the Helmholtz Gemeinschaft; DFG Cluster of Excellence "Origin and
Structure of the Universe,"; DFG Collaborative Research Centers
[SFB823/C4, SFB876/C3]; Polish MNiSzW [745/N-HESS-MAGIC/2010/0]; US
Department of Energy Office of Science; US National Science Foundation;
Smithsonian Institution; NSERC in Canada; Science Foundation Ireland
(SFI) [10/RFP/AST2748]; STFC in the UK; Istituto Nazionale di
Astrofisica in Italy; Centre National d'Etudes Spatiales in France; NASA
[GO0-11120X]; Associated Universities, Inc.; European Community [227290]
Attila Abramowski
F. Acero
Felix A. Aharonian
A. G. Akhperjanian
Gisela Anton
Arnim Balzer
Anna Barnacka
U. Barres de Almeida
Yvonne Becherini
J. Becker
B. Behera
K. Bernlöhr
E. Birsin
Jonathan Biteau
A. Bochow
Catherine Boisson
J. Bolmont
Pol Bordas
J. Brucker
Francois Brun
Pierre Brun
Tomasz Bulik
I. Buesching
Svenja Carrigan
Sabrina Casanova
M. Cerruti
Paula M. Chadwick
A. Charbonnier
Ryan C. G. Chaves
A. Cheesebrough
A. C. Clapson
G. Coignet
Gabriele Cologna
Jan Conrad
M. Dalton
M. K. Daniel
I. D. Davids
B. Degrange
C. Deil
H. J. Dickinson
A. Djannati-Ataï
W. Domainko
L. O'C. Drury
G. Dubus
K. Dutson
J. Dyks
M. Dyrda
Kathrin Egberts
P. Eger
P. Espigat
L. Fallon
C. Farnier
S. Fegan
F. Feinstein
M. V. Fernandes
A. Fiasson
G. Fontaine
A. Foerster
M. Fuessling
Y. A. Gallant
H. Gast
L. Gerard
D. Gerbig
B. Giebels
J. F. Glicenstein
B. Glueck
P. Goret
D. Goering
S. Haeffner
J. D. Hague
D. Hampf
M. Hauser
S. Heinz
G. Heinzelmann
G. Henri
G. Hermann
James Anthony Hinton
A. Hoffmann
W. Hofmann
P. Hofverberg
M. Holler
D. Horns
A. Jacholkowska
O. C. de Jager
C. Jahn
M. Jamrozy
I. Jung
M. A. Kastendieck
K. Katarzynski
U. Katz
S. Kaufmann
D. Keogh
D. Khangulyan
B. Khelifi
D. Klochkov
W. Kluzniak
T. Kneiske
Nu. Komin
K. Kosack
R. Kossakowski
H. Laffon
G. Lamanna
D. Lennarz
T. Lohse
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V. Marandon
A. Marcowith
J. Masbou
D. Maurin
N. Maxted
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C. M. Hui
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
S. LeBohec
G. Maier
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
P. D. Nunez
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
A. Varlotta
V. V. Vassiliev
M. Vivier
S. P. Wakely
T. C. Weekes
D. A. Williams
B. Zitzer
U. Barres de Almeida
M. Cara
C. Casadio
C. C. Cheung
W. McConville
F. Davies
A. Doi
G. Giovannini
M. Giroletti
K. Hada
P. Hardee
D. E. Harris
W. Junor
M. Kino
N. P. Lee
C. Ly
J. Madrid
F. Massaro
C. G. Mundell
H. Nagai
E. S. Perlman
I. A. Steele
R. C. Walker
D. L. Wood
eng
uncontrolled
galaxies: active
eng
uncontrolled
galaxies: individual (M 87)
eng
uncontrolled
galaxies: jets
eng
uncontrolled
galaxies: nuclei
eng
uncontrolled
gamma rays: galaxies
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert
37044
2011
2011
eng
26
2
727
article
IOP Publ. Ltd.
Bristol
Fermi-LAT Collaboration, MAGIC Collaboration, VERITAS Collaboration
1
--
--
--
Insights into the high-energy gamma-Ray emission of markarian 501 fromextensive multifrequency observations in the fermi era
We report on the gamma-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) gamma-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 +/- 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 +/- 0.14, and the softest one is 2.51 +/- 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size less than or similar to 0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (similar or equal to 10(44) erg s(-1)) constitutes only a small fraction (similar to 10(-3)) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/727/2/129
0004-637X
wos:2011-2013
129
WOS:000286662000068
Paneque, D (reprint author), Stanford Univ, Dept Phys, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA., dpaneque@mppmu.mpg.de; stawarz@astro.isas.jaxa.jp
K. A. Wallenberg Foundation; International Doctorate on Astroparticle
Physics (IDAPP) program; INFN Padova; Academy of Finland [212656,
210338]; National Radio Astronomy Observatory's Very Long Baseline Array
(VLBA) [BK150, BP143, MOJAVE]; Russian RFBR foundation [09-02-00092];
Georgian National Science Foundation [GNSF/ST07/4-180]; NASA
[NNX08AW31G]; NSF [AST-0808050]
A. A. Abdo
Margit Ackermann
M. Ajello
A. J. Allafort
L. Baldini
J. Ballet
G. Barbiellini
M. G. Baring
D. Bastieri
K. C. Bechtol
R. Bellazzini
B. Berenji
R. D. Blandford
E. D. Bloom
E. Bonamente
A. W. Borgland
A. Bouvier
T. J. Brandt
Johan Bregeon
A. Brez
M. Brigida
P. Bruel
R. Buehler
S. Buson
G. A. Caliandro
R. A. Cameron
A. Cannon
P. A. Caraveo
Svenja Carrigan
J. M. Casandjian
E. Cavazzuti
C. Cecchi
O. Celik
E. Charles
A. Chekhtman
C. C. Cheung
J. Chiang
S. Ciprini
R. Claus
J. Cohen-Tanugi
Jan Conrad
S. Cutini
C. D. Dermer
F. de Palma
E. do Couto e Silva
P. S. Drell
R. Dubois
D. Dumora
C. Favuzzi
S. J. Fegan
E. C. Ferrara
W. B. Focke
P. Fortin
M. Frailis
L. Fuhrmann
Y. Fukazawa
S. Funk
P. Fusco
F. Gargano
D. Gasparrini
N. Gehrels
S. Germani
N. Giglietto
F. Giordano
M. Giroletti
T. Glanzman
G. Godfrey
I. A. Grenier
L. Guillemot
S. Guiriec
M. Hayashida
E. Hays
D. Horan
R. E. Hughes
G. Johannesson
A. S. Johnson
W. N. Johnson
M. Kadler
T. Kamae
H. Katagiri
J. Kataoka
J. Knoedlseder
M. Kuss
J. Lande
L. Latronico
S. -H. Lee
M. Lemoine-Goumard
F. Longo
F. Loparco
B. Lott
M. N. Lovellette
P. Lubrano
G. M. Madejski
A. Makeev
W. Max-Moerbeck
Mario Nicola Mazziotta
J. E. McEnery
J. Mehault
P. F. Michelson
W. Mitthumsiri
T. Mizuno
A. A. Moiseev
C. Monte
M. E. Monzani
A. Morselli
I. V. Moskalenko
S. Murgia
M. Naumann-Godo
S. Nishino
P. L. Nolan
J. P. Norris
E. Nuss
T. Ohsugi
A. Okumura
N. Omodei
E. Orlando
J. F. Ormes
D. Paneque
J. H. Panetta
D. Parent
V. Pavlidou
T. J. Pearson
V. Pelassa
M. Pepe
M. Pesce-Rollins
F. Piron
T. A. Porter
S. Raino
R. Rando
M. Razzano
A. Readhead
A. Reimer
O. Reimer
J. L. Richards
J. Ripken
S. Ritz
M. Roth
H. F. -W. Sadrozinski
D. Sanchez
A. Sander
J. D. Scargle
C. Sgro
E. J. Siskind
P. D. Smith
G. Spandre
P. Spinelli
L. Stawarz
M. Stevenson
M. S. Strickman
K. V. Sokolovsky
D. J. Suson
H. Takahashi
T. Takahashi
T. Tanaka
J. B. Thayer
J. G. Thayer
D. J. Thompson
L. Tibaldo
F. Torres
G. Tosti
A. Tramacere
Y. Uchiyama
T. L. Usher
J. Vandenbroucke
V. Vasileiou
N. Vilchez
V. Vitale
A. P. Waite
P. Wang
A. E. Wehrle
B. L. Winer
K. S. Wood
Z. Yang
T. Ylinen
J. A. Zensus
M. Ziegler
J. Aleksic
L. A. Antonelli
P. Antoranz
Michael Backes
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
A. Berdyugin
K. Berger
E. Bernardini
A. Biland
O. Blanch Bigas
R. K. Bock
A. Boller
G. Bonnoli
Pol Bordas
D. Borla Tridon
Valentin Bosch-Ramon
D. Bose
I. Braun
T. Bretz
M. Camara
E. Carmona
A. Carosi
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
F. Dazzi
A. de Angelis
E. De Cea del Pozo
B. De Lotto
M. De Maria
F. De Sabata
C. Delgado Mendez
A. Diago Ortega
M. Doert
A. Dominguez
Dijana Dominis Prester
D. Dorner
M. Doro
D. Elsaesser
D. Ferenc
M. V. Fonseca
L. Font
R. J. Garcia Lopen
M. Garczarczyk
M. Gaug
G. Giavitto
N. Godinovi
D. Hadasch
A. Herrero
D. Hildebrand
D. Hoehne-Moench
J. Hose
D. Hrupec
T. Jogler
S. Klepser
T. Kraehenbuehl
D. Kranich
J. Krause
A. La Barbera
E. Leonardo
E. Lindfors
S. Lombardi
M. Lopez
E. Lorenz
P. Majumdar
E. Makariev
G. Maneva
N. Mankuzhiyil
K. Mannheim
L. Maraschi
M. Mariotti
M. Martinez
D. Mazin
M. Meucci
J. M. Miranda
R. Mirzoyan
H. Miyamoto
J. Moldon
A. Moralejo
D. Nieto
K. Nilsson
R. Orito
I. Oya
R. Paoletti
J. M. Paredes
S. Partini
M. Pasanen
F. Pauss
R. G. Pegna
M. A. Perez-Torres
M. Persic
J. Peruzzo
J. Pochon
P. G. Prada Moroni
F. Prada
E. Prandini
N. Puchades
I. Puljak
T. Reichardt
R. Reinthal
W. Rhode
M. Ribo
J. Rico
M. Rissi
S. Ruegamer
A. Saggion
K. Saito
T. Y. Saito
M. Salvati
M. Sanchez-Conde
K. Satalecka
V. Scalzotto
V. Scapin
C. Schultz
T. Schweizer
M. Shayduk
S. N. Shore
A. Sierpowska-Bartosik
A. Sillanpaa
J. Sitarek
D. Sobczynska
F. Spanier
S. Spiro
A. Stamerra
B. Steinke
J. Storz
N. Strah
J. C. Struebig
T. Suric
L. O. Takalo
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
H. Vankov
R. M. Wagner
Q. Weitzel
V. Zabalza
F. Zandanel
R. Zanin
V. A. Acciari
T. Arlen
T. Aune
W. Benbow
D. Boltuch
S. M. Bradbury
J. H. Buckley
V. Bugaev
A. Cannon
A. Cesarini
L. Ciupik
W. Cui
R. Dickherber
M. Errando
A. Falcone
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
D. Huang
C. M. Hui
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
A. Konopelko
H. Krawczynski
F. Krennrich
M. J. Lang
G. Maier
S. McArthur
A. McCann
M. McCutcheon
P. Moriarty
R. Mukherjee
R. Ong
N. Otte
D. Pandel
J. S. Perkins
A. Pichel
M. Pohl
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
A. C. Rovero
M. Schroedter
G. H. Sembroski
G. D. Senturk
D. Steele
S. P. Swordy
G. Tesic
M. Theiling
S. Thibadeau
A. Varlotta
S. Vincent
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
M. Wood
B. Zitzer
M. Villata
C. M. Raiteri
H. D. Aller
M. F. Aller
A. A. Arkharov
D. A. Blinov
P. Calcidese
W. P. Chen
N. V. Efimova
G. Kimeridze
T. S. Konstantinova
E. N. Kopatskaya
E. Koptelova
O. M. Kurtanidze
S. O. Kurtanidze
A. Lahteenmaki
V. M. Larionov
E. G. Larionova
L. V. Larionova
R. Ligustri
D. A. Morozova
M. G. Nikolashvili
L. A. Sigua
I. S. Troitsky
E. Angelakis
M. Capalbi
A. Carraminana
L. Carrasco
P. Cassaro
E. de la Fuente
M. A. Gurwell
Y. Y. Kovalev
Yu. A. Kovalev
T. P. Krichbaum
H. A. Krimm
Paolo Leto
M. L. Lister
G. Maccaferri
J. W. Moody
Y. Mori
I. Nestoras
A. Orlati
C. Pagani
C. Pace
R. Pearson
M. Perri
B. G. Piner
A. B. Pushkarev
E. Ros
A. C. Sadun
T. Sakamoto
M. Tornikoski
Y. Yatsu
A. Zook
eng
uncontrolled
acceleration of particles
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual (Mrk 501)
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: general
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert
38157
2014
2014
eng
14
2
780
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration, HESS Collaboration
1
--
--
--
Long-term TeV and X-RAY observations of the GAMMA- RAY binary hess J0632+057
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/780/2/168
0004-637X
1538-4357
wos:2014
168
WOS:000329097100055
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., afalcone@astro.psu.edu; gernot.maier@desy.de; pol.bordas@uni-tuebingen.de
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; Helmholtz Association;
European Community [ERC-StG-259391]; German Ministry for Education and
Research (BMBF); Max Planck Society; French Ministry for Research;
CNRS-IN2P3; Astroparticle Interdisciplinary Programme of the CNRS; U.K.
Particle Physics and Astronomy Research Council (PPARC); IPNP of the
Charles University; South African Department of Science and Technology
and National Research Foundation; University of Namibia
E. Aliu
S. Archambault
T. Aune
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
X. Chen
L. Ciupik
M. P. Connolly
W. Cui
C. Duke
J. Dumm
M. Errando
A. Falcone
S. Federici
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
A. McCann
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
M. Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
J. Rousselle
G. H. Sembroski
F. Sheidaei
C. Skole
A. W. Smith
D. Staszak
M. Stroh
Igor O. Telezhinsky
M. Theiling
J. V. Tucci
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
A. Weinstein
R. Welsing
D. A. Williams
A. Zajczyk
B. Zitzer
Attila Abramowski
Felix A. Aharonian
Faical Ait Benkhali
A. G. Akhperjanian
Ekrem Oǧuzhan Angüner
Gisela Anton
Shangkari Balenderan
Arnim Balzer
Anna Barnacka
Yvonne Becherini
J. Becker Tjus
K. Bernlöhr
E. Birsin
E. Bissaldi
Jonathan Biteau
Markus Boettcher
Catherine Boisson
J. Bolmont
Pol Bordas
J. Brucker
Francois Brun
Pierre Brun
Tomasz Bulik
Svenja Carrigan
Sabrina Casanova
M. Cerruti
Paula M. Chadwick
R. Chalme-Calvet
Ryan C. G. Chaves
A. Cheesebrough
M. Chretien
Sergio Colafrancesco
Gabriele Cologna
Jan Conrad
C. Couturier
M. Dalton
M. K. Daniel
I. D. Davids
B. Degrange
C. Deil
P. deWilt
H. J. Dickinson
A. Djannati-Ataï
W. Domainko
G. Dubus
K. Dutson
J. Dyks
M. Dyrda
T. Edwards
Kathrin Egberts
P. Eger
P. Espigat
C. Farnier
S. Fegan
F. Feinstein
M. V. Fernandes
D. Fernandez
A. Fiasson
G. Fontaine
A. Foerster
M. Fuessling
M. Gajdus
Y. A. Gallant
T. Garrigoux
G. Giavitto
B. Giebels
J. F. Glicenstein
M. -H. Grondin
M. Grudzinska
S. Haeffner
J. Hahn
J. Harris
G. Heinzelmann
G. Henri
G. Hermann
O. Hervet
A. Hillert
James Anthony Hinton
W. Hofmann
P. Hofverberg
M. Holler
D. Horns
A. Jacholkowska
C. Jahn
M. Jamrozy
M. Janiak
F. Jankowsky
I. Jung
M. A. Kastendieck
K. Katarzynski
U. Katz
S. Kaufmann
B. Khelifi
M. Kieffer
S. Klepser
D. Klochkov
W. Kluzniak
T. Kneiske
D. Kolitzus
Nu. Komin
K. Kosack
S. Krakau
F. Krayzel
P. P. Krueger
H. Laffon
G. Lamanna
J. Lefaucheur
A. Lemiere
M. Lemoine-Goumard
J. -P. Lenain
D. Lennarz
T. Lohse
A. Lopatin
C. -C. Lu
V. Marandon
A. Marcowith
R. Marx
G. Maurin
N. Maxted
M. Mayer
T. J. L. McComb
J. Mehault
U. Menzler
M. Meyer
R. Moderski
M. Mohamed
E. Moulin
T. Murach
C. L. Naumann
M. de Naurois
J. Niemiec
S. J. Nolan
L. Oakes
S. Ohm
E. de Ona Wilhelmi
B. Opitz
M. Ostrowski
I. Oya
M. Panter
R. D. Parsons
M. Paz Arribas
N. W. Pekeur
G. Pelletier
J. Perez
P. -O. Petrucci
B. Peyaud
S. Pita
H. Poon
G. Puehlhofer
M. Punch
A. Quirrenbach
S. Raab
M. Raue
A. Reimer
O. Reimer
M. Renaud
R. de los Reyes
F. Rieger
L. Rob
C. Romoli
S. Rosier-Lees
G. Rowell
B. Rudak
C. B. Rulten
V. Sahakian
David M. Sanchez
A. Santangelo
R. Schlickeiser
F. Schuessler
A. Schulz
U. Schwanke
S. Schwarzburg
S. Schwemmer
H. Sol
G. Spengler
F. Spies
L. Stawarz
R. Steenkamp
Christian Stegmann
F. Stinzing
K. Stycz
Iurii Sushch
A. Szostek
J. -P. Tavernet
T. Tavernier
A. M. Taylor
R. Terrier
M. Tluczykont
C. Trichard
K. Valerius
C. van Eldik
G. Vasileiadis
C. Venter
A. Viana
P. Vincent
H. J. Voelk
F. Volpe
M. Vorster
S. J. Wagner
P. Wagner
M. Ward
M. Weidinger
Q. Weitzel
R. White
A. Wierzcholska
P. Willmann
A. Woernlein
D. Wouters
M. Zacharias
A. Zajczyk
A. A. Zdziarski
Alraune Zech
H. -S. Zechlin
eng
uncontrolled
acceleration of particles
eng
uncontrolled
binaries: general
eng
uncontrolled
gamma rays: general(HESS J0632+057, VER J0633+057)
Institut für Physik und Astronomie
Referiert
54802
2017
2017
eng
30
603
article
EDP Sciences
Les Ulis
MAGIC Collaboration;VERITAS Collaboration
1
2017-07-04
2017-07-04
--
Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009
Aims. We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1, which includes, among other instruments, MAGIC, VERITAS, Whipple 10 m, and Fermi-LAT to cover the gamma-ray range from 0.1 GeV to 20 TeV; RXTE and Swift to cover wavelengths from UV to hard X-rays; and GASP-WEBT, which provides coverage of radio and optical wavelengths. Optical polarization measurements were provided for a fraction of the campaign by the Steward and St. Petersburg observatories. We evaluate the variability of the source and interband correlations, the gamma-ray flaring activity occurring in May 2009, and interpret the results within two synchrotron self-Compton (SSC) scenarios. Methods. The multiband variability observed during the full campaign is addressed in terms of the fractional variability, and the possible correlations are studied by calculating the discrete correlation function for each pair of energy bands where the significance was evaluated with dedicated Monte Carlo simulations. The space of SSC model parameters is probed following a dedicated grid-scan strategy, allowing for a wide range of models to be tested and offering a study of the degeneracy of model-to-data agreement in the individual model parameters, hence providing a less biased interpretation than the "single-curve SSC model adjustment" typically reported in the literature. Results. We find an increase in the fractional variability with energy, while no significant interband correlations of flux changes are found on the basis of the acquired data set. The SSC model grid-scan shows that the flaring activity around May 22 cannot be modeled adequately with a one-zone SSC scenario (using an electron energy distribution with two breaks), while it can be suitably described within a two (independent) zone SSC scenario. Here, one zone is responsible for the quiescent emission from the averaged 4.5-month observing period, while the other one, which is spatially separated from the first, dominates the flaring emission occurring at X-rays and very-high-energy (> 100 GeV, VHE) gamma-rays. The flaring activity from May 1, which coincides with a rotation of the electric vector polarization angle (EVPA), cannot be satisfactorily reproduced by either a one-zone or a two-independent-zone SSC model, yet this is partially affected by the lack of strictly simultaneous observations and the presence of large flux changes on sub-hour timescales (detected at VHE gamma rays). Conclusions. The higher variability in the VHE emission and lack of correlation with the X-ray emission indicate that, at least during the 4.5-month observing campaign in 2009, the highest energy (and most variable) electrons that are responsible for the VHE gamma rays do not make a dominant contribution to the similar to 1 keV emission. Alternatively, there could be a very variable component contributing to the VHE gamma-ray emission in addition to that coming from the SSC scenario. The studies with our dedicated SSC grid-scan show that there is some degeneracy in both the one-zone and the two-zone SSC scenarios probed, with several combinations of model parameters yielding a similar model-to-data agreement, and some parameters better constrained than others. The observed gamma-ray flaring activity, with the EVPA rotation coincident with the first gamma-ray flare, resembles those reported previously for low frequency peaked blazars, hence suggesting that there are many similarities in the flaring mechanisms of blazars with different jet properties.
Astronomy and astrophysics : an international weekly journal
10.1051/0004-6361/201629540
1432-0746
wos:2017
A31
WOS:000406619100031
Paneque, D (reprint author), Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany.; Doert, M (reprint author), Tech Univ Dortmund, D-44221 Dortmund, Germany., marlene.doert@tu-dortmund.de; dpaneque@mppmu.mpg.de
German BMBF; German MPG; Italian INFN; Italian INAF; Swiss National Fund SNF; ERDF under the Spanish MINECO [FPA2015-69818-P, FPA2012-36668, FPA2015-68278-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2013-47447-C3-1-P, AYA2015-71042-P, ESP2015-71662-C2-2-P, CSD2009-00064]; Japanese JSPS; Japanese MEXT; Spanish Centro de Excelencia "Severo Ochoa" [SEV-2012-0234, SEV-2015-0548]; Unidad de Excelencia "Maria de Maeztu" [MDM-2014-0369]; Academy of Finland [268740, 212656, 210338, 121148]; Croatian Science Foundation (HrZZ) [09/176]; University of Rijeka [13.12.1.3.02]; DFG Collaborative Research Centers [SFB823/C4, SFB876/C3]; Polish MNiSzW [745/N-HESS-MAGIC/2010/0]; US Department of Energy Office of Science; US National Science Foundation; NSERC in Canada; Science Foundation Ireland [SFI 10/RFP/AST2748]; INAF in Italy; CNES in France; Russian RFBR [15-02-00949]; St. Petersburg University [6.38.335.2015]; Shota Rustaveli National Science Foundation [FR/577/6-320/13]; Smithsonian Institution; Academia Sinica; NASA [NNX08AW31G, NNX08AW56G]; NSF [AST-0808050]; STFC in the UK
2022-04-14T12:06:46+00:00
sword
importub
filename=package.tar
c0dae962a496f214e1e80f3b1e37ed46
false
true
M. L. Ahnen
S. Ansoldi
L. A. Antonelli
P. Antoranz
A. Babic
B. Banerjee
P. Bangale
U. Barres de Almeida
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
E. Bernardini
A. Berti
B. Biasuzzi
A. Biland
O. Blanch
S. Bonnefoy
G. Bonnoli
F. Borracci
T. Bretz
S. Buson
A. Carosi
A. Chatterjee
R. Clavero
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Da Vela
F. Dazzi
A. De Angelis
B. De Lotto
E. de Ona Wilhelmi
F. Di Pierro
M. Doert
A. Dominguez
D. Dominis Prester
D. Dorner
M. Doro
S. Einecke
D. Eisenacher Glawion
D. Elsaesser
M. Engelkemeier
V. Fallah Ramazani
A. Fernandez-Barral
D. Fidalgo
M. V. Fonseca
L. Font
K. Frantzen
C. Fruck
D. Galindo
R. J. Garcia Lopez
M. Garczarczyk
D. Garrido Terrats
M. Gaug
P. Giammaria
N. Godinovic
A. Gonzalez Munoz
D. Gora
D. Guberman
D. Hadasch
A. Hahn
Y. Hanabata
M. Hayashida
J. Herrera
J. Hose
D. Hrupec
G. Hughes
W. Idec
K. Kodani
Y. Konno
H. Kubo
J. Kushida
A. La Barbera
D. Lelas
E. Lindfors
S. Lombardi
F. Longo
M. Lopez
R. Lopez-Coto
P. Majumdar
M. Makariev
K. Mallot
G. Maneva
M. Manganaro
K. Mannheim
L. Maraschi
B. Marcote
M. Mariotti
M. Martinez
D. Mazin
U. Menzel
J. M. Miranda
R. Mirzoyan
A. Moralejo
E. Moretti
D. Nakajima
V. Neustroev
A. Niedzwiecki
M. Nievas Rosillo
K. Nilsson
K. Nishijima
K. Noda
L. Nogues
A. Overkemping
S. Paiano
J. Palacio
M. Palatiello
D. Paneque
R. Paoletti
J. M. Paredes
X. Paredes-Fortuny
G. Pedaletti
M. Peresano
L. Perri
M. Persic
J. Poutanen
P. G. Prada Moroni
E. Prandini
I. Puljak
I. Reichardt
W. Rhode
M. Ribo
J. Rico
J. Rodriguez Garcia
T. Saito
K. Satalecka
S. Schroder
C. Schultz
T. Schweizer
S. N. Shore
A. Sillanpaa
J. Sitarek
I. Snidaric
D. Sobczynska
A. Stamerra
T. Steinbring
M. Strzys
T. Suric
L. Takalo
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
J. Thaele
D. F. Torres
T. Toyama
A. Treves
G. Vanzo
V. Verguilov
I. Vovk
J. E. Ward
M. Will
M. H. Wu
R. Zanin
A. U. Abeysekara
S. Archambault
A. Archer
W. Benbow
R. Bird
M. Buchovecky
J. H. Buckley
V. Bugaev
M. P. Connolly
W. Cui
H. J. Dickinson
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
A. Flinders
L. Fortson
G. H. Gillanders
S. Griffin
J. Grube
M. Huetten
D. Hanna
J. Holder
T. B. Humensky
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
M. J. Lang
G. Maier
A. McCann
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
N. Otte
N. Park
J. Perkins
A. Pichel
M. Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
C. Rulten
I. Sadeh
M. Santander
G. H. Sembroski
K. Shahinyan
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. P. Wakely
A. Weinstein
P. Wilcox
Alina Wilhelm
D. A. Williams
B. Zitzer
S. Razzaque
M. Villata
C. M. Raiteri
H. D. Aller
M. F. Aller
V. M. Larionov
A. A. Arkharov
D. A. Blinov
N. V. Efimova
T. S. Grishina
V. A. Hagen-Thorn
E. N. Kopatskaya
L. V. Larionova
E. G. Larionova
D. A. Morozova
I. S. Troitsky
R. Ligustri
P. Calcidese
A. Berdyugin
O. M. Kurtanidze
M. G. Nikolashvili
G. N. Kimeridze
L. A. Sigua
S. O. Kurtanidze
R. A. Chigladze
W. P. Chen
E. Koptelova
T. Sakamoto
A. C. Sadun
J. W. Moody
C. Pace
R. Pearson
Y. Yatsu
Y. Mori
A. Carraminyana
L. Carrasco
E. de la Fuente
J. P. Norris
P. S. Smith
A. Wehrle
M. A. Gurwell
A. Zook
C. Pagani
M. Perri
M. Capalbi
A. Cesarini
H. A. Krimm
Y. Y. Kovalev
Yu. A. Kovalev
E. Ros
A. B. Pushkarev
M. L. Lister
K. V. Sokolovsky
M. Kadler
G. Piner
A. Lahteenmaki
M. Tornikoski
E. Angelakis
T. P. Krichbaum
I. Nestoras
L. Fuhrmann
J. A. Zensus
P. Cassaro
A. Orlati
G. Maccaferri
P. Leto
M. Giroletti
J. L. Richards
W. Max-Moerbeck
A. C. S. Readhead
eng
uncontrolled
BL Lacertae objects: individual: Markarian 501
eng
uncontrolled
methods: data analysis
Physik
Institut für Physik und Astronomie
Referiert
Import
38516
2015
2015
eng
22
1
812
article
IOP Publ. Ltd.
Bristol
NuSTAR Team, MAGIC Collaboration, VERITAS Collaboration, F-Gamma Consortium
1
--
--
--
First NuSTAR observations of MRK 501 within a radio to TeV multi-instrument campaign
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsahovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/812/1/65
0004-637X
1538-4357
wos:2015
65
WOS:000364234700065
Furniss, A (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA., amy.@gmail.com; nodak5@gmail.com; josefa.becerra@nasa.gov
NASA [NNG08FD60C, NNX08AW31G, NNX11A043G]; National Aeronautics and
Space Administration; German BMBF; German MPG; Italian INFN; Italian
INAF; Swiss National Fund SNF; ERDF under the Spanish MINECO; Japanese
JSPS; Japanese MEXT; Centro de Excelencia Severo Ochoa project of the
Spanish Consolider-Ingenio programme [SEV-2012-0234]; Academy of Finland
[268740]; Croatian Science Foundation (HrZZ) Project [09/176];
University of Rijeka Project [13.12.1.3.02]; DFG Collaborative Research
Centers [SFB823/C4, SFB876/C3]; Polish MNiSzW grant
[745/N-HESS-MAGIC/2010/0]; U.S. Department of Energy Office of Science;
U.S. National Science Foundation; Smithsonian Institution; NSERC in
Canada; Science Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the
U.K; INSU/CNRS (France); MPG (Germany); IGN (Spain); International Max
Planck Research School (IMPRS) for Astronomy and Astrophysics at the
University of Bonn; NSF [AST-0808050, AST-1109911]; Istanbul University
[49429, 48285]; Bilim Akademisi (BAGEP program); TUBITAK [13AT100-431,
13AT100-466, 13AT60-430]; Russian RFBR grant [15-02-00949]; St.
Petersburg University research grant [6.38.335.2015]; NASA Fermi Guest
Investigator grant [NNX14AQ58G]; Swift Guest Investigator grant
[NNX14AI96G]; BU; Lowell Observatory; Scientific Research Fund of the
Bulgarian Ministry of Education and Sciences [DO 02-137 (BIn-13/09)];
Shota Rustaveli National Science Foundation [FR/577/6-320/13]; Institute
of Astronomy; Rozhen National Astronomical Observatory, Bulgarian
Academy of Sciences; Ministry of Education, Science and Technological
Development of the Republic of Serbia [176011, 176004, 176021]; CPAN
project of the Spanish Consolider-Ingenio programme [CSD2007-00042];
MultiDark project of the Spanish Consolider-Ingenio programme
[CSD2009-00064]; International Max Planck Research School (IMPRS) for
Astronomy and Astrophysics at the University of Cologne
A. Furniss
K. Noda
S. Boggs
J. Chiang
F. Christensen
W. Craig
P. Giommi
C. Hailey
F. Harisson
G. Madejski
K. Nalewajko
M. Perri
D. Stern
M. Urry
F. Verrecchia
W. Zhang
M. L. Ahnen
S. Ansoldi
L. A. Antonelli
P. Antoranz
A. Babic
B. Banerjee
P. Bangale
U. Barres de Almeida
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
E. Bernardini
B. Biasuzzi
A. Biland
O. Blanch Bigas
S. Bonnefoy
G. Bonnoli
F. Borracci
T. Bretz
E. Carmona
A. Carosi
A. Chatterjee
R. Clavero
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Da Vela
F. Dazzi
A. De Angelis
G. De Caneva
B. De Lotto
E. de Ona Wilhelmi
C. Delgado Mendez
F. Di Pierro
Dijana Dominis Prester
D. Dorner
M. Doro
S. Einecke
D. Eisenacher Glawion
D. Elsaesser
A. Fernandez-Barral
D. Fidalgo
M. V. Fonseca
L. Font
K. Frantzen
C. Fruck
D. Galindo
R. J. Garcia Lopez
M. Garczarczyk
D. Garrido Terrats
M. Gaug
P. Giammaria
N. Godinovic
A. Gonzalez Munoz
D. Guberman
Y. Hanabata
M. Hayashida
J. Herrera
J. Hose
D. Hrupec
G. Hughes
W. Idec
H. Kellermann
K. Kodani
Y. Konno
H. Kubo
J. Kushida
A. La Barbera
D. Lelas
N. Lewandowska
E. Lindfors
S. Lombardi
F. Longo
M. Lopez
R. Lopez-Coto
A. Lopez-Oramas
E. Lorenz
P. Majumdar
M. Makariev
K. Mallot
G. Maneva
M. Manganaro
K. Mannheim
L. Maraschi
B. Marcote
M. Mariotti
M. Martinez
D. Mazin
U. Menzel
J. M. Miranda
R. Mirzoyan
A. Moralejo
D. Nakajima
V. Neustroev
A. Niedzwiecki
M. Nievas Rosillo
K. Nilsson
K. Nishijima
R. Orito
A. Overkemping
S. Paiano
J. Palacio
M. Palatiello
D. Paneque
R. Paoletti
J. M. Paredes
X. Paredes-Fortuny
M. Persic
J. Poutanen
P. G. Prada Moroni
E. Prandini
I. Puljak
R. Reinthal
W. Rhode
M. Ribo
J. Rico
J. Rodriguez Garcia
T. Saito
K. Saito
K. Satalecka
V. Scapin
C. Schultz
T. Schweizer
S. N. Shore
A. Sillanpaa
J. Sitarek
I. Snidaric
D. Sobczynska
A. Stamerra
T. Steinbring
M. Strzys
L. Takalo
H. Takami
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
J. Thaele
D. F. Torres
T. Toyama
A. Treves
V. Verguilov
I. Vovk
M. Will
R. Zanin
A. Archer
W. Benbow
R. Bird
Jonathan Biteau
V. Bugaev
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
L. Gerard
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
Nils Hakansson
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
M. J. Lang
T. T. Y. Lin
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
N. Park
D. Petry
Martin Pohl
A. Popkow
K. Ragan
G. Ratliff
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
M. Santander
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
V. V. Vassiliev
S. P. Wakely
O. M. Weiner
A. Weinstein
Alina Wilhelm
D. A. Williams
B. Zitzer
O. Vince
L. Fuhrmann
E. Angelakis
V. Karamanavis
I. Myserlis
T. P. Krichbaum
J. A. Zensus
H. Ungerechts
A. Sievers
R. Bachev
Markus Boettcher
W. P. Chen
G. Damljanovic
C. Eswaraiah
T. Guver
T. Hovatta
Z. Hughes
S. I. Ibryamov
M. D. Joner
B. Jordan
S. G. Jorstad
M. Joshi
J. Kataoka
O. M. Kurtanidze
S. O. Kurtanidze
A. Lahteenmaki
G. Latev
H. C. Lin
V. M. Larionov
A. A. Mokrushina
D. A. Morozova
M. G. Nikolashvili
C. M. Raiteri
V. Ramakrishnan
A. C. R. Readhead
A. C. Sadun
L. A. Sigua
E. H. Semkov
A. Strigachev
J. Tammi
M. Tornikoski
Y. V. Troitskaya
I. S. Troitsky
M. Villata
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
galaxies: individual (Markarian 501)
eng
uncontrolled
X-rays: galaxies
Institut für Physik und Astronomie
Referiert
39022
2015
2015
eng
18
576
article
EDP Sciences
Les Ulis
MAGIC Collaboration, VERITAS Collaboration, MAGIC Collaboration
1
--
--
--
The 2009 multiwavelength campaign on Mrk 421: Variability and correlation studies
Aims. We perform an extensive characterization of the broadband emission of Mrk 421, as well as its temporal evolution, during the non-flaring (low) state. The high brightness and nearby location (z = 0.031) of Mrk 421 make it an excellent laboratory to study blazar emission. The goal is to learn about the physical processes responsible for the typical emission of Mrk 421, which might also be extended to other blazars that are located farther away and hence are more difficult to study.
Methods. We performed a 4.5-month multi-instrument campaign on Mrk 421 between January 2009 and June 2009, which included VLBA, F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other instruments and collaborations. This extensive radio to very-high-energy (VHE; E > 100 GeV) gamma-ray dataset provides excellent temporal and energy coverage, which allows detailed studies of the evolution of the broadband spectral energy distribution.
Results. Mrk421 was found in its typical (non-flaring) activity state, with a VHE flux of about half that of the Crab Nebula, yet the light curves show significant variability at all wavelengths, the highest variability being in the X-rays. We determined the power spectral densities (PSD) at most wavelengths and found that all PSDs can be described by power-laws without a break, and with indices consistent with pink/red-noise behavior. We observed a harder-when-brighter behavior in the X-ray spectra and measured a positive correlation between VHE and X-ray fluxes with zero time lag. Such characteristics have been reported many times during flaring activity, but here they are reported for the first time in the non-flaring state. We also observed an overall anti-correlation between optical /UV and X-rays extending over the duration of the campaign.
Conclusions. The harder-when-brighter behavior in the X-ray spectra and the measured positive X-ray/VHE correlation during the 2009 multiwavelength campaign suggests that the physical processes dominating the emission during non-flaring states have similarities with those occurring during flaring activity. In particular, this observation supports leptonic scenarios as being responsible for the emission of Mrk 421 during non-flaring activity. Such a temporally extended X-ray /VHE correlation is not driven by any single flaring event, and hence is difficult to explain within the standard hadronic scenarios. The highest variability is observed in the X-ray band, which, within the one-zone synchrotron self-Compton scenario, indicates that the electron energy distribution is most variable at the highest energies.
Astronomy and astrophysics : an international weekly journal
10.1051/0004-6361/201424216
0004-6361
1432-0746
wos:2015
A126
WOS:000357274600061
Nowak, N (reprint author), Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany., nina.nowak@astro.su.se; dpaneque@mppmu.mpg.de
German BMBF and MPG; Italian INFN and INAF; Swiss National Fund SNF;
ERDF under the Spanish MINECO; Japanese JSPS; MEXT; Centro de Excelencia
Severo Ochoa [SEV-2012-0234]; CPAN [CSD2007-00042]; Spanish
Consolider-Ingenio [CSD2009-00064]; Academy of Finland [268740, 212656,
210338, 121148]; Croatian Science Foundation [09/176]; University of
Rijeka [13.12.1.3.02]; DFG Collaborative Research Centers [SFB823/C4,
SFB876/C3]; Polish MNiSzW [745/N-HESS-MAGIC/2010/0]; US Department of
Energy; US National Science Foundation; Smithsonian Institution; NSERC
in Canada; Science Foundation Ireland; STCF in the UK; NASA [NNX08AW31G,
NNX11A043G]; NSF [AST-0808050, AST-1109911]; Shota Rustaveli National
Science Foundation [FR/577/6-320/13]; Russian RFBR foundation
[09-02-00092]
J. Aleksic
S. Ansoldi
L. A. Antonelli
P. Antoranz
A. Babic
P. Bangale
U. Barres de Almeida
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
K. Berger
E. Bernardini
A. Bilandli
O. Bianch
R. K. Bock
S. Bonnefoy
G. Bonnoli
F. Borracci
T. Bretz
E. Carmona
A. Carosi
D. Carreto Fidalgo
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Da Vela
F. Dazzi
A. De Angelis
G. De Caneva
B. De Lotto
C. Delgado Mendez
M. Doert
A. Dominguez
Dijana Dominis Prester
D. Dorner
M. Doro
S. Einecke
D. Eisenacher
D. Elsaesser
E. Farina
D. Ferenc
M. V. Fonseca
L. Font
K. Frantzen
C. Fruck
R. J. Garcia Lopez
M. Garczarczyki
D. Garrido Terrats
M. Gaug
G. Giavitto
N. Godinovic
A. Gonzalez Munoz
S. R. Gozzini
A. Hadamek
D. Hadasch
A. Herrero
D. Hildebrand
J. Hose
D. Hrupec
W. Idec
V. Kadenius
H. Kellermann
M. L. Knoetig
J. Krause
J. Kushida
A. La Barbera
D. Lelas
N. Lewandowska
E. Lindfors
F. Longo
S. Lombardi
M. Lopez
R. Lopez-Coto
A. Lopez-Oramas
E. Lorenz
I. Lozano
M. Makariev
K. Mallot
G. Maneva
N. Mankuzhiyil
K. Mannheim
L. Maraschi
B. Marcote
M. Mariotti
M. Martinez
D. Mazin
U. Menzel
M. Meucci
J. M. Miranda
R. Mirzoyan
A. Moralejo
P. Munar-Adrover
D. Nakajima
A. Niedzwiecki
K. Nilsson
N. Nowak
R. Orito
A. Overkemping
S. Paiano
M. Palatiello
D. Paneque
R. Paoletti
J. M. Paredes
X. Paredes-Fortuny
S. Partini
M. Persic
F. Prada
P. G. Prada Moroni
E. Prandini
S. Preziuso
I. Puljak
R. Reinthal
W. Rhode
M. Ribo
J. Rico
J. Rodriguez Garcia
S. Ruegamer
A. Saggion
K. Saito
M. Salvati
K. Satalecka
V. Scalzotto
V. Scapin
C. Schuliz
T. Schweizer
S. N. Shore
A. Sillanpaa
J. Sitarek
I. Snidaric
D. Sobczynska
F. Spanier
V. Stamatescu
A. Stamerra
T. Steinbring
J. Storz
S. Sun
T. Suric
L. Takalo
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
J. Thaele
O. Tibolla
D. F. Torres
T. Toyama
A. Treves
M. Uellenbeck
P. Vogler
R. M. Wagner
F. Zandanel
R. Zanin
S. Archambault
B. Behera
M. Beilicke
W. Benbow
R. Bird
J. H. Buckley
V. Bugaev
M. Cerruti
X. Chen
L. Ciupik
E. Collins-Hughes
W. Cui
J. Dumm
J. D. Eisch
A. Falcone
S. Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
K. Meagher
P. Moriarty
R. Mukherjee
R. A. Ong
A. N. Otte
N. Park
A. Pichel
M. Pohl
A. Popkow
H. Prokoph
M. J. Quinn
K. Ragan
J. Rajotte
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. V. Tucci
J. Tyler
A. Varlotta
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
M. Villata
C. Raiteri
H. D. Aller
M. F. Aller
W. P. Chen
B. Jordan
E. Koptelova
O. M. Kurtanidze
A. Lahteenmaki
B. McBreen
V. M. Larionov
C. S. Lin
M. G. Nikolashvili
E. Angelakis
M. Capalbi
A. Carraminana
L. Carrasco
P. Cassaro
A. Cesarini
L. Fuhrmann
M. Giroletti
T. Hovatta
T. P. Krichbaum
H. A. Krimm
W. Max-Moerbeck
J. W. Moody
G. Maccaferri
Y. Mori
I. Nestoras
A. Orlati
C. Pace
R. Pearson
M. Perri
A. C. S. Readhead
J. L. Richards
A. C. Sadun
T. Sakamoto
J. Tammi
M. Tornikoski
Y. Yatsu
A. Zook
eng
uncontrolled
BL Lacertae objects: individual: Mrk 421
Institut für Physik und Astronomie
Referiert
51609
2018
2018
eng
18
1
866
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration Fermi-LAT Collaboration HAWC Collaboration
1
2018-10-05
2018-10-05
--
VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog
The High Altitude Water Cherenkov (HAWC) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100 GeV) gamma-ray sources based on 507 days of observation. Among these, 19 sources are not associated with previously known teraelectronvolt (TeV) gamma-ray sources. We have studied 14 of these sources without known counterparts with VERITAS and Fermi-LAT. VERITAS detected weak gamma-ray emission in the 1 TeV-30 TeV band in the region of DA 495, a pulsar wind nebula coinciding with 2HWC J1953+294, confirming the discovery of the source by HAWC. We did not find any counterpart for the selected 14 new HAWC sources from our analysis of Fermi-LAT data for energies higher than 10 GeV. During the search, we detected gigaelectronvolt (GeV) gamma-ray emission coincident with a known TeV pulsar wind nebula, SNR G54.1+0.3 (VER J1930+188), and a 2HWC source, 2HWC J1930+188. The fluxes for isolated, steady sources in the 2HWC catalog are generally in good agreement with those measured by imaging atmospheric Cherenkov telescopes. However, the VERITAS fluxes for SNR G54.1+0.3, DA 495, and TeV J2032+4130 are lower than those measured by HAWC, and several new HAWC sources are not detected by VERITAS. This is likely due to a change in spectral shape, source extension, or the influence of diffuse emission in the source region.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/1538-4357/aade4e
0004-637X
1538-4357
wos:2018
24
WOS:000446752400024
Park, N (reprint author), Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA., npark7@wisc.edu; john.w.hewitt@unf.edu; itaboada@gatech.edu
2021-08-27T06:45:08+00:00
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Park, N.
Hewitt, J. W.
false
true
A. U. Abeysekara
A. Archer
Wystan Benbow
Ralph Bird
Robert Brose
M. Buchovecky
J. H. Buckley
V. Bugaev
A. J. Chromey
M. P. Connolly
Wei Cui
M. K. Daniel
A. Falcone
Qi Feng
John P. Finley
L. Fortson
Amy Furniss
M. Huetten
David Hanna
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
Caitlin A. Johnson
Philip Kaaret
P. Kar
M. Kertzman
David Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
T. T. Y. Lin
S. McArthur
P. Moriarty
Reshmi Mukherjee
R. A. Ong
Adam Nepomuk Otte
Nahee Park
A. Petrashyk
Martin Pohl
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
Gregory T. Richards
E. Roache
C. Rulten
I. Sadeh
Marcos Santander
G. H. Sembroski
Karlen Shahinyan
I. Sushch
J. Tyler
S. P. Wakely
A. Weinstein
R. M. Wells
P. Wilcox
Alina Wilhelm
D. A. Williams
T. J. Williamson
B. Zitzer
S. Abdollahi
Marco Ajello
Luca Baldini
G. Barbiellini
Denis Bastieri
Ronaldo Bellazzini
B. Berenji
Elisabetta Bissaldi
R. D. Blandford
R. Bonino
E. Bottacini
Terri J. Brandt
P. Bruel
R. Buehler
R. A. Cameron
R. Caputo
P. A. Caraveo
D. Castro
E. Cavazzuti
Eric Charles
G. Chiaro
S. Ciprini
Johann Cohen-Tanugi
D. Costantin
S. Cutini
F. de Palma
N. Di Lalla
M. Di Mauro
L. Di Venere
A. Dominguez
C. Favuzzi
S. J. Fegan
Anna Franckowiak
Yasushi Fukazawa
Stefan Funk
Piergiorgio Fusco
Fabio Gargano
Dario Gasparrini
Nicola Giglietto
F. Giordano
Marcello Giroletti
D. Green
I. A. Grenier
L. Guillemot
Sylvain Guiriec
Elizabeth Hays
John W. Hewitt
D. Horan
G. Johannesson
S. Kensei
M. Kuss
Stefan Larsson
L. Latronico
Marianne Lemoine-Goumard
J. Li
Francesco Longo
Francesco Loparco
M. N. Lovellette
Pasquale Lubrano
Jeffrey D. Magill
Simone Maldera
Mario Nicola Mazziotta
J. E. McEnery
P. F. Michelson
W. Mitthumsiri
Tsunefumi Mizuno
Maria Elena Monzani
Aldo Morselli
Igor V. Moskalenko
M. Negro
E. Nuss
R. Ojha
Nicola Omodei
M. Orienti
E. Orlando
M. Palatiello
Vaidehi S. Paliya
D. Paneque
Jeremy S. Perkins
M. Persic
Melissa Pesce-Rollins
Vahe' Petrosian
F. Piron
Troy A. Porter
G. Principe
S. Raino
Riccardo Rando
B. Rani
Massimilano Razzano
Soebur Razzaque
A. Reimer
Olaf Reimer
T. Reposeur
C. Sgro
E. J. Siskind
Gloria Spandre
P. Spinelli
D. J. Suson
Hiroyasu Tajima
J. B. Thayer
David J. Thompson
Diego F. Torres
Gino Tosti
Eleonora Troja
J. Valverde
Giacomo Vianello
M. Vogel
K. Wood
M. Yassine
R. Alfaro
C. Alvarez
J. D. Alvarez
R. Arceo
J. C. Arteaga-Velazquez
D. Avila Rojas
H. A. Ayala Solares
A. Becerril
E. Belmont-Moreno
S. Y. BenZvi
A. Bernal
J. Braun
C. Brisbois
K. S. Caballero-Mora
T. Capistran
A. Carraminana
Sabrina Casanova
M. Castillo
U. Cotti
J. Cotzomi
S. Coutino de Leon
C. De Leon
E. De la Fuente
S. Dichiara
B. L. Dingus
M. A. DuVernois
J. C. Diaz-Velez
K. Engel
O. Enriquez-Rivera
D. W. Fiorino
H. Fleischhack
N. Fraija
J. A. Garcia-Gonzalez
F. Garfias
A. Gonzalez Munoz
M. M. Gonzalez
J. A. Goodman
Z. Hampel-Arias
J. P. Harding
S. Hernandez
A. Hernandez-Almada
B. Hona
F. Hueyotl-Zahuantitla
C. M. Hui
P. Huntemeyer
A. Iriarte
A. Jardin-Blicq
V. Joshi
S. Kaufmann
A. Lara
R. J. Lauer
W. H. Lee
D. Lennarz
H. Leon Vargas
J. T. Linnemann
A. L. Longinotti
G. Luis-Raya
R. Luna-Garcia
R. Lopez-Coto
K. Malone
S. S. Marinelli
O. Martinez
I. Martinez-Castellanos
J. Martinez-Castro
H. Martinez-Huerta
J. A. Matthews
P. Miranda-Romagnoli
E. Moreno
M. Mostafa
A. Nayerhoda
L. Nellen
M. Newbold
M. U. Nisa
R. Noriega-Papaqui
R. Pelayo
J. Pretz
E. G. Perez-Perez
Z. Ren
C. D. Rho
C. Riviere
D. Rosa-Gonzalez
M. Rosenberg
E. Ruiz-Velasco
H. Salazar
F. Salesa Greus
A. Sandoval
M. Schneider
M. Seglar Arroyo
G. Sinnis
A. J. Smith
R. W. Springer
P. Surajbali
Ignacio Taboada
O. Tibolla
K. Tollefson
I. Torres
Tilan N. Ukwatta
L. Villasenor
T. Weisgarber
Stefan Westerhoff
I. G. Wisher
J. Wood
Tolga Yapici
G. Yodh
A. Zepeda
H. Zhou
eng
uncontrolled
gamma rays: general
Astronomie und zugeordnete Wissenschaften
Physik
Institut für Physik und Astronomie
Referiert
Import
Green Open-Access
38849
2015
2015
eng
26
578
article
EDP Sciences
Les Ulis
MAGIC Collaboration, VERITAS Collaboration
1
--
--
--
Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010
Context. Because of its proximity, Mrk 421 is one of the best sources on which to study the nature of BL Lac objects. Its proximity allows us to characterize its broadband spectral energy distribution (SED).
Aims. The goal is to better understand the mechanisms responsible for the broadband emission and the temporal evolution of Mrk 421. These mechanisms may also apply to more distant blazars that cannot be studied with the same level of detail.
Methods. A flare occurring in March 2010 was observed for 13 consecutive days (from MJD 55 265 to MJD 55 277) with unprecedented wavelength coverage from radio to very high energy (VHE; E > 100 GeV) gamma-rays with MAGIC, VERITAS, Whipple, Fermi-LAT, MAXI, RXTE, Swift, GASP-WEBT, and several optical and radio telescopes. We modeled the day-scale SEDs with one-zone and two-zone synchrotron self-Compton (SSC) models, investigated the physical parameters, and evaluated whether the observed broadband SED variability can be associated with variations in the relativistic particle population.
Results. The activity of Mrk 421 initially was high and then slowly decreased during the 13-day period. The flux variability was remarkable at the X-ray and VHE bands, but it was minor or not significant at the other bands. The variability in optical polarization was also minor. These observations revealed an almost linear correlation between the X-ray flux at the 2-10 keV band and the VHE gamma-ray flux above 200 GeV, consistent with the gamma-rays being produced by inverse-Compton scattering in the Klein-Nishina regime in the framework of SSC models. The one-zone SSC model can describe the SED of each day for the 13 consecutive days reasonably well, which once more shows the success of this standard theoretical scenario to describe the SEDs of VHE BL Lacs such as Mrk 421. This flaring activity is also very well described by a two-zone SSC model, where one zone is responsible for the quiescent emission, while the other smaller zone, which is spatially separated from the first, contributes to the daily variable emission occurring at X-rays and VHE gamma-rays. The second blob is assumed to have a smaller volume and a narrow electron energy distribution with 3 x 10(4) < gamma < 6 x 10(5), where. is the Lorentz factor of the electrons. Such a two-zone scenario would naturally lead to the correlated variability at the X-ray and VHE bands without variability at the optical/UV band, as well as to shorter timescales for the variability at the X-ray and VHE bands with respect to the variability at the other bands.
Conclusions. Both the one-zone and the two-zone SSC models can describe the daily SEDs via the variation of only four or five model parameters, under the hypothesis that the variability is associated mostly with the underlying particle population. This shows that the particle acceleration and cooling mechanism that produces the radiating particles might be the main mechanism responsible for the broadband SED variations during the flaring episodes in blazars. The two-zone SSC model provides a better agreement with the observed SED at the narrow peaks of the low-and high-energy bumps during the highest activity, although the reported one-zone SSC model could be further improved by varying the parameters related to the emitting region itself (delta, B and R), in addition to the parameters related to the particle population.
Astronomy and astrophysics : an international weekly journal
10.1051/0004-6361/201424811
0004-6361
1432-0746
wos:2015
A22
WOS:000357502600034
Paneque, D (reprint author), Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany., dpaneque@mpp.mpg.de; sysun@mpp.mpg.de; takami@post.kek.jp
German BMBF; German MPG; Italian INFN; Italian INAF; Swiss National Fund
SNF; ERDF under the Spanish MINECO; Japanese JSPS; Japanese MEXT; Centro
de Excelencia Severo Ochoa project of the Spanish Consolider-Ingenio
programme [SEV-2012-0234]; CPAN project of the Spanish
Consolider-Ingenio programme [CSD2007-00042]; MultiDark project of the
Spanish Consolider-Ingenio programme [CSD2009-00064]; Academy of Finland
[268740, 212656, 210338, 121148]; Croatian Science Foundation (HrZZ)
Project [09/176]; University of Rijeka [13.12.1.3.02]; DFG Collaborative
Research Centers [SFB823/C4, SFB876/C3]; Polish MNiSzW
[745/N-HESS-MAGIC/2010/0]; US Department of Energy Office of Science; US
National Science Foundation; Smithsonian Institution; NSERC in Canada;
Science Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the UK; NASA
[NNX11AQ03G, NNX08AW31G, NNX11A043G]; Academia Sinica; NSF [AST-0808050,
AST-1109911]; Russian RFBR [12-02-00452]; St. Petersburg University
[6.0.163.2010, 6.38.71.2012]; Georgian National Science Foundation
[GNSF/ST07/4-180]; Shota Rustaveli National Science Foundation
[FR/577/6-320/13]
J. Aleksic
S. Ansoldi
L. A. Antonelli
P. Antoranz
A. Babic
P. Bangale
U. Barres de Almeida
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
E. Bernardini
B. Biasuzzi
A. Biland
O. Blanch Bigas
A. Boller
S. Bonnefoy
G. Bonnoli
F. Borracci
T. Bretz
E. Carmona
A. Carosi
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Da Vela
F. Dazzi
A. De Angelis
G. De Caneva
B. De Lotto
E. de Ona Wilhelmi
C. Delgado Mendez
Dijana Dominis Prester
D. Dorner
M. Doro
S. Einecke
D. Eisenacher
D. Elsaesser
M. V. Fonseca
L. Font
K. Frantzen
C. Fruck
D. Galindo
R. J. Garcia Lopez
M. Garczarczyk
D. Garrido Terrats
M. Gaug
N. Godinovic
A. Gonzalez Munoz
S. R. Gozzini
D. Hadasch
Y. Hanabata
M. Hayashida
J. Herrera
D. Hildebrand
J. Hose
D. Hrupec
G. Hughes
W. Idec
V. Kadenius
H. Kellermann
M. L. Knoetig
K. Kodani
Y. Konno
J. Krause
H. Kubo
J. Kushida
A. La Barbera
D. Lelas
N. Lewandowska
E. Lindfors
S. Lombardi
M. Lopez
R. Lopez-Coto
A. Lopez-Oramas
E. Lorenz
I. Lozano
M. Makariev
K. Mallot
G. Maneva
N. Mankuzhiyil
K. Mannheim
L. Maraschi
B. Marcote
M. Mariotti
M. Martinez
D. Mazin
U. Menzel
J. M. Miranda
R. Mirzoyan
A. Moralejo
P. Munar-Adrover
D. Nakajima
A. Niedzwiecki
K. Nilsson
K. Nishijima
K. Noda
R. Orito
A. Overkemping
S. Paiano
M. Palatiello
D. Paneque
R. Paoletti
J. M. Paredes
X. Paredes-Fortuny
M. Persic
P. G. Prada Moroni
E. Prandini
I. Puljak
R. Reinthal
W. Rhode
M. Ribo
J. Rico
J. Rodriguez Garcia
S. Rugamer
T. Saito
K. Saito
K. Satalecka
V. Scalzotto
V. Scapin
C. Schultz
T. Schweizer
S. Sun
S. N. Shore
A. Sillanpaa
J. Sitarek
I. Snidaric
D. Sobczynska
F. Spanier
V. Stamatescu
A. Stamerra
T. Steinbring
B. Steinke
J. Storz
M. Strzys
L. Takalo
H. Takami
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
J. Thaele
O. Tibolla
D. F. Torres
T. Toyama
A. Treves
M. Uellenbeck
P. Vogler
R. Zanin
S. Archambault
A. Archer
M. Beilicke
W. Benbow
K. Berger
R. Bird
Jonathan Biteau
J. H. Buckley
V. Bugaev
M. Cerruti
Xiaoming Chen
L. Ciupik
E. Collins-Hughes
W. Cui
J. D. Eisch
A. Falcone
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
G. Gyuk
Nils Hakansson
J. Holder
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
D. Kieda
M. J. Lang
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. A. Ong
A. N. Otte
J. S. Perkins
A. Pichel
Manuela Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
K. Ragan
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
S. P. Wakely
R. Welsing
Alina Wilhelm
D. A. Williams
S. Buson
J. Finke
M. Villata
C. Raiteri
H. D. Aller
M. F. Aller
A. Cesarini
W. P. Chen
M. A. Gurwell
S. G. Jorstad
G. N. Kimeridze
E. Koptelova
O. M. Kurtanidze
S. O. Kurtanidze
A. Lahteenmaki
V. M. Larionov
E. G. Larionova
H. C. Lin
B. McBreen
J. W. Moody
D. A. Morozova
A. P. Marscher
W. Max-Moerbeck
M. G. Nikolashvili
M. Perri
A. C. S. Readhead
J. L. Richards
J. A. Ros
A. C. Sadun
T. Sakamoto
L. A. Sigua
P. S. Smith
M. Tornikoski
I. S. Troitsky
A. E. Wehrle
B. Jordan
eng
uncontrolled
radiation mechanisms: non-thermal
eng
uncontrolled
galaxies: active
eng
uncontrolled
BL Lacertae objects: individual: Mrk 421
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
47134
2018
2018
eng
23
620
article
EDP Sciences
Les Ulis
MAGIC Collaboration FACT Collaboration VERITAS Collaboration
1
--
--
--
Extreme HBL behavior of Markarian 501 during 2012
Aims. We aim to characterize the multiwavelength emission from Markarian 501 (Mrk 501), quantify the energy-dependent variability, study the potential multiband correlations, and describe the temporal evolution of the broadband emission within leptonic theoretical scenarios. Methods. We organized a multiwavelength campaign to take place between March and July of 2012. Excellent temporal coverage was obtained with more than 25 instruments, including the MAGIC, FACT and VERITAS Cherenkov telescopes, the instruments on board the Swift and Fermi spacecraft, and the telescopes operated by the GASP-WEBT collaboration. Results. Mrk 501 showed a very high energy (VHE) gamma-ray flux above 0.2 TeV of similar to 0.5 times the Crab Nebula flux (CU) for most of the campaign. The highest activity occurred on 2012 June 9, when the VHE flux was similar to 3 CU, and the peak of the high-energy spectral component was found to be at similar to 2 TeV. Both the X-ray and VHE gamma-ray spectral slopes were measured to be extremely hard, with spectral indices <2 during most of the observing campaign, regardless of the X-ray and VHE flux. This study reports the hardest Mrk 501 VHE spectra measured to date. The fractional variability was found to increase with energy, with the highest variability occurring at VHE. Using the complete data set, we found correlation between the X-ray and VHE bands; however, if the June 9 flare is excluded, the correlation disappears (significance <3 sigma) despite the existence of substantial variability in the X-ray and VHE bands throughout the campaign. Conclusions. The unprecedentedly hard X-ray and VHE spectra measured imply that their low- and high-energy components peaked above 5 keV and 0.5 TeV, respectively, during a large fraction of the observing campaign, and hence that Mrk 501 behaved like an extreme high-frequency-peaked blazar (EHBL) throughout the 2012 observing season. This suggests that being an EHBL may not be a permanent characteristic of a blazar, but rather a state which may change over time. The data set acquired shows that the broadband spectral energy distribution (SED) of Mrk 501, and its transient evolution, is very complex, requiring, within the framework of synchrotron self-Compton (SSC) models, various emission regions for a satisfactory description. Nevertheless the one-zone SSC scenario can successfully describe the segments of the SED where most energy is emitted, with a significant correlation between the electron energy density and the VHE gamma-ray activity, suggesting that most of the variability may be explained by the injection of high-energy electrons. The one-zone SSC scenario used reproduces the behavior seen between the measured X-ray and VHE gamma-ray fluxes, and predicts that the correlation becomes stronger with increasing energy of the X-rays.
Astronomy and astrophysics : an international weekly journal / European Southern Observatory (ESO)
10.1051/0004-6361/201833704
1432-0746
wos:2018
A181
WOS:000453301200012
Hughes, G (reprint author), Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland.; Paneque, D (reprint author), Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany.; Shukla, A (reprint author), Univ Wurzburg, D-97074 Wurzburg, Germany.; Hughes, G (reprint author), Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA., dpaneque@mppmu.mpg.de; amit.shukla@astro.uni-wuerzburg.de; gareth.hughes@cfa.harvard.edu
German BMBFFederal Ministry of Education & Research (BMBF); MPGMax Planck Society; Italian INFNIstituto Nazionale di Fisica Nucleare; INAF; Swiss National Fund SNFSwiss National Science Foundation (SNSF); ERDF under the Spanish MINECO [FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, CSD2009-00064]; Japanese JSPSMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of Science; MEXTMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT); Spanish Centro de Excelencia "Severo Ochoa" [SEV-2012-0234, SEV-2015-0548]; Unidad de Excelencia "Maria de Maeztu" [MDM-2014-0369]; Croatian Science Foundation (HrZZ) [09/176]; University of Rijeka Project [13.12.1.3.02]; DFG Collaborative Research CentersGerman Research Foundation (DFG) [SFB823/C4, SFB876/C3]; Polish National Research Centre [UMO-2016/22/M/ST9/00382]; Brazilian MCTIC; CNPqNational Council for Scientific and Technological Development (CNPq); FAPERJCarlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro (FAPERJ); U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; National Aeronautics and Space AdministrationNational Aeronautics & Space Administration (NASA); DOEUnited States Department of Energy (DOE) [DE-AC02-76SF00515]; Russian Science FoundationRussian Science Foundation (RSF) [17-12-01029]; Shota Rustaveli NSF [FR/577/6-320/13]; Bulgarian National Science Fund of the Ministry of Education and Science [DN 08-1/2016, DN 18-13/2017]; UK Science and Technology Facilities CouncilScience & Technology Facilities Council (STFC); Fermi Guest Investigator grants [NNX09AU10G, NNX12AO93G]; NASANational Aeronautics & Space Administration (NASA) [NNX08AW31G, NNX11A043G, NNX14AQ89G]; NSFNational Science Foundation (NSF) [AST-0808050, AST-1109911]; [PRIN-SKA-CTA-INAF2016]
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2020-06-15T11:26:51+00:00
filename=package.tar
7dedb51ec37908fce552a8c759a30a63
M. L. Ahnen
S. Ansoldi
L. A. Antonelli
C. Arcaro
A. Babic
B. Banerjee
P. Bangale
U. Barres de Almeida
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
E. Bernardini
A. Berti
W. Bhattacharyya
O. Blanch
G. Bonnoli
R. Carosi
A. Carosi
A. Chatterjee
S. M. Colak
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Cumani
P. Da Vela
F. Dazzi
A. De Angelis
B. De Lotto
M. Delfino
Jose Miguel Martins Delgado
F. Di Pierro
M. Doert
A. Dominguez
D. Dominis Prester
M. Doro
D. Eisenacher Glawion
M. Engelkemeier
V. Fallah Ramazani
A. Fernandez-Barral
D. Fidalgo
M. V. Fonseca
L. Font
C. Fruck
D. Galindo
R. J. Garcia Lopez
M. Garczarczyk
M. Gaug
P. Giammaria
N. Godinovic
D. Gora
D. Guberman
D. Hadasch
A. Hahn
T. Hassan
M. Hayashida
J. Herrera
J. Hose
D. Hrupec
K. Ishio
Y. Konno
H. Kubo
J. Kushida
D. Kuvezdic
D. Lelas
E. Lindfors
S. Lombardi
F. Longo
M. Lopez
C. Maggio
P. Majumdar
M. Makariev
G. Maneva
M. Manganaro
L. Maraschi
M. Mariotti
M. Martinez
D. Mazin
U. Menzel
M. Minev
J. M. Miranda
R. Mirzoyan
A. Moralejo
V. Moreno
E. Moretti
T. Nagayoshi
V. Neustroev
A. Niedzwiecki
M. Nievas Rosillo
C. Nigro
K. Nilsson
D. Ninci
K. Nishijima
K. Noda
L. Nogues
S. Paiano
J. Palacio
D. Paneque
R. Paoletti
J. M. Paredes
G. Pedaletti
M. Peresano
L. Perri
M. Persic
P. G. Prada Moroni
E. Prandini
I. Puljak
J. R. Garcia
I. Reichardt
M. Ribo
J. Rico
C. Righi
A. Rugliancich
T. Saito
K. Satalecka
S. Schroeder
T. Schweizer
S. N. Shore
J. Sitarek
I. Snidaric
D. Sobczynska
A. Stamerra
M. Strzys
T. Suric
L. Takalo
F. Tavecchio
P. Temnikov
T. Terzic
M. Teshima
N. Torres-Alba
A. Treves
S. Tsujimoto
G. Vanzo
M. Vazquez Acosta
I. Vovk
J. E. Ward
M. Will
D. Zaric
A. Arbet-Engels
D. Baack
M. Balbo
A. Biland
M. Blank
T. Bretz
K. Bruegge
M. Bulinski
J. Buss
A. Dmytriiev
D. Dorner
S. Einecke
D. Elsaesser
T. Herbst
D. Hildebrand
L. Kortmann
L. Linhoff
M. Mahlke
K. Mannheim
S. A. Mueller
D. Neise
A. Neronov
M. Noethe
J. Oberkirch
A. Paravac
W. Rhode
B. Schleicher
F. Schulz
K. Sedlaczek
A. Shukla
V. Sliusar
R. Walter
A. Archer
W. Benbow
R. Bird
Robert Brose
J. H. Buckley
V. Bugaev
J. L. Christiansen
W. Cui
M. K. Daniel
A. Falcone
Q. Feng
J. P. Finley
G. H. Gillanders
O. Gueta
D. Hanna
O. Hervet
J. Holder
G. Hughes
M. Huetten
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
T. T. Y. Lin
G. Maier
S. McArthur
P. Moriarty
R. Mukherjee
R. A. Ong
A. N. Otte
N. Park
A. Petrashyk
A. Pichel
Martin Pohl
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
C. Rulten
I. Sadeh
M. Santander
G. H. Sembroski
K. Shahinyan
Iurii Sushch
J. Tyler
S. P. Wakely
A. Weinstein
R. M. Wells
P. Wilcox
A. Wilhel
D. A. Williams
T. J. Williamson
B. Zitzer
M. Perri
F. Verrecchia
C. Leto
M. Villata
C. M. Raiteri
S. G. Jorstad
V. M. Larionov
D. A. Blinov
T. S. Grishina
E. N. Kopatskaya
E. G. Larionova
A. A. Nikiforova
D. A. Morozova
Yu. V. Troitskaya
I. S. Troitsky
O. M. Kurtanidze
M. G. Nikolashvili
S. O. Kurtanidze
G. N. Kimeridze
R. A. Chigladze
A. Strigachev
A. C. Sadun
eng
uncontrolled
astroparticle physics
eng
uncontrolled
acceleration of particles
eng
uncontrolled
radiation mechanisms: non-thermal
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual: Mrk501
Institut für Physik und Astronomie
Referiert
Open Access
Import
Bronze Open-Access
39386
2015
2015
eng
12
573
article
EDP Sciences
Les Ulis
MAGIC Collaboration, VERITAS Collaboration
1
--
--
--
Multiwavelength observations of Mrk 501 in 2008
Context. Blazars are variable sources on various timescales over a broad energy range spanning from radio to very high energy (>100 GeV, hereafter VHE). Mrk 501 is one of the brightest blazars at TeV energies and has been extensively studied since its first VHE detection in 1996. However, most of the gamma-ray studies performed on Mrk 501 during the past years relate to flaring activity, when the source detection and characterization with the available gamma-ray instrumentation was easier to perform.
Aims. Our goal is to characterize the source gamma-ray emission in detail, together with the radio-to-X-ray emission, during the non-flaring (low) activity, which is less often studied than the occasional flaring (high) activity.
Methods. We organized a multiwavelength (MW) campaign on Mrk 501 between March and May 2008. This multi-instrument effort included the most sensitive VHE gamma-ray instruments in the northern hemisphere, namely the imaging atmospheric Cherenkov telescopes MAGIC and VERITAS, as well as Swift, RXTE, the F-GAMMA, GASP-WEBT, and other collaborations and instruments. This provided extensive energy and temporal coverage of Mrk 501 throughout the entire campaign.
Results. Mrk 501 was found to be in a low state of activity during the campaign, with a VHE flux in the range of 10%-20% of the Crab nebula flux. Nevertheless, significant flux variations were detected with various instruments, with a trend of increasing variability with energy and a tentative correlation between the X-ray and VHE fluxes. The broadband spectral energy distribution during the two different emission states of the campaign can be adequately described within the homogeneous one-zone synchrotron self-Compton model, with the (slightly) higher state described by an increase in the electron number density.
Conclusions. The one-zone SSC model can adequately describe the broadband spectral energy distribution of the source during the two months covered by the MW campaign. This agrees with previous studies of the broadband emission of this source during flaring and non-flaring states. We report for the first time a tentative X-ray-to-VHE correlation during such a low VHE activity. Although marginally significant, this positive correlation between X-ray and VHE, which has been reported many times during flaring activity, suggests that the mechanisms that dominate the X-ray/VHE emission during non-flaring-activity are not substantially different from those that are responsible for the emission during flaring activity.
Astronomy and astrophysics : an international weekly journal
10.1051/0004-6361/201322906
0004-6361
1432-0746
wos:2015
A50
WOS:000346901300005
Paneque, D (reprint author), Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany., mankuzhiyil.nijil@gmail.com; dpaneque@mppmu.mpg.de; konstancjas@googlemail.com
German BMBF; MPG; Italian INFN; Swiss National Fund SNF; Spanish MICINN;
CPAN [CSD2007-00042]; MultiDark projects of the Spanish
Consolider-Ingenio programme [CSD2009-00064]; Bulgarian NSF [DO02-353];
Academy of Finland [127740]; Croatian science Foundation [Projekt
09/176]; DFG Cluster of Excellence "Origin and Structure of the
Universe"; DFG [SFB823/C4, SFB876/C3]; Polish MNiSzW
[745/N-HESS-MAGIC/2010/0]; US Department of Energy Office of Science; US
National Science Foundation; Smithsonian Institution; NSERC in Canada;
Science Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the UK; Russian
RFBR foundation [12-02-00452]; Georgian National Science Foundation
[GNSF/ST07/180]; Academy of Finland to our observing projects [212656,
210338, 121148]; Ministry of Education and Science of the Russian
Federation [14.518.11.7054]; Russian Foundation for Basic Research
[13-02-12103]
J. Aleksic
S. Ansoldi
L. A. Antonelli
P. Antoranz
A. Babic
P. Bangale
U. Barres de Almeida
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
K. Berger
E. Bernardini
A. Biland
O. Blanch Bigas
R. K. Bock
S. Bonnefoy
G. Bonnoli
F. Borracci
T. Bretz
E. Carmona
A. Carosi
D. Carreto Fidalgo
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Da Vela
F. Dazzi
A. De Angelis
G. De Caneva
B. De Lotto
C. Delgado Mendez
M. Doert
A. Dominguez
Dijana Dominis Prester
D. Dorner
M. Doro
S. Einecke
D. Eisenacher
D. Elsaesser
E. Farina
D. Ferenc
M. V. Fonseca
L. Font
K. Frantzen
C. Fruck
R. J. Garcia Lopez
M. Garczarczyk
D. Garrido Terrats
M. Gaug
G. Giavitto
N. Godinovic
A. Gonzalez Munoz
S. R. Gozzini
A. Hadamek
D. Hadasch
A. Herrero
D. Hildebrand
J. Hose
D. Hrupec
W. Idec
V. Kadenius
H. Kellermann
M. L. Knoetig
J. Krause
J. Kushida
A. La Barbera
D. Lelas
N. Lewandowska
E. Lindfors
S. Lombardi
M. Lopez
R. Lopez-Coto
A. Lopez-Oramas
E. Lorenz
I. Lozano
M. Makariev
K. Mallot
G. Maneva
N. Mankuzhiyil
K. Mannheim
L. Maraschi
B. Marcote
M. Mariotti
M. Martinez
D. Mazin
U. Menzel
M. Meucci
J. M. Miranda
R. Mirzoyan
A. Moralejo
P. Munar-Adrover
D. Nakajima
A. Niedzwiecki
K. Nilsson
N. Nowak
R. Orito
A. Overkemping
S. Paiano
M. Palatiello
D. Paneque
R. Paoletti
J. M. Paredes
X. Paredes-Fortuny
S. Partini
M. Persic
F. Prada
P. G. Prada Moroni
E. Prandini
S. Preziuso
I. Puljak
R. Reinthal
W. Rhode
M. Ribo
J. Rico
J. Rodriguez Garcia
S. Ruegamer
A. Saggion
T. Saito
K. Saito
M. Salvati
K. Satalecka
V. Scalzotto
V. Scapin
C. Schultz
T. Schweizer
S. N. Shore
A. Sillanpaa
J. Sitarek
I. Snidaric
D. Sobczynska
F. Spanier
V. Stamatescu
A. Stamerra
T. Steinbring
J. Storz
S. Sun
T. Suric
L. Takalo
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
J. Thaele
O. Tibolla
D. F. Torres
T. Toyama
A. Treves
M. Uellenbeck
P. Vogler
R. M. Wagner
F. Zandanel
R. Zanin
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
A. Bouvier
V. Bugaev
M. Cerruti
Xuhui Chen
L. Ciupik
E. Collins-Hughes
W. Cui
C. Duke
J. Dumm
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
C. A. Johnson
P. Kaaret
M. Kertzman
D. Kieda
H. Krawczynski
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
K. Meagher
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
A. Pichel
Manula Pohl
A. Popkow
H. Prokoph
J. Quinn
J. Rajotte
G. Ratliff
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
K. Shahinyan
F. Sheidaei
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
T. C. Weekes
R. Welsing
D. A. Williams
A. Zajczyk
B. Zitzer
M. Villata
C. M. Raiteri
M. Ajello
M. Perri
H. D. Aller
M. F. Aller
V. M. Larionov
N. V. Efimova
T. S. Konstantinova
E. N. Kopatskaya
W. P. Chen
E. Koptelova
H. Y. Hsiao
O. M. Kurtanidze
M. G. Nikolashvili
G. N. Kimeridze
B. Jordan
Paolo Leto
C. S. Buemi
C. Trigilio
G. Umana
A. Lahteenmaki
E. Nieppola
M. Tornikoski
J. Sainio
V. Kadenius
M. Giroletti
A. Cesarini
L. Fuhrmann
Yu. A. Kovalev
Y. Y. Kovalev
eng
uncontrolled
astroparticle physics
eng
uncontrolled
BL Lacertae objects: individual: Mrk 501
eng
uncontrolled
gamma rays: general
Institut für Physik und Astronomie
Referiert
51461
2018
2018
eng
8
1
867
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration MAGIC Collaboration
1
--
2018-10-31
--
Periastron Observations of TeV Gamma-Ray Emission from a Binary System with a 50-year Period
We report on observations of the pulsar/Be star binary system PSR J2032+4127/MT91 213 in the energy range between 100 GeV and 20 TeV with the Very Energetic Radiation Imaging Telescope Array and Major Atmospheric Gamma Imaging Cherenkov telescope arrays. The binary orbit has a period of approximately 50 years, with the most recent periastron occurring on 2017 November 13. Our observations span from 18 months prior to periastron to one month after. A new point-like gamma-ray source is detected, coincident with the location of PSR J2032+4127/MT91 213. The gamma-ray light curve and spectrum are well characterized over the periastron passage. The flux is variable over at least an order of magnitude, peaking at periastron, thus providing a firm association of the TeV source with the pulsar/Be star system. Observations prior to periastron show a cutoff in the spectrum at an energy around 0.5 TeV. This result adds a new member to the small population of known TeV binaries, and it identifies only the second source of this class in which the nature and properties of the compact object are firmly established. We compare the gamma-ray results with the light curve measured with the X-ray Telescope on board the Neil Gehrels Swift Observatory and with the predictions of recent theoretical models of the system. We conclude that significant revision of the models is required to explain the details of the emission that we have observed, and we discuss the relationship between the binary system and the overlapping steady extended source, TeV J2032+4130.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.3847/2041-8213/aae70e
2041-8205
2041-8213
wos:2018
L19
WOS:000448968100003
Bird, R (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA., ralphbird@astro.ucla.edu; tjwilli@udel.edu; jaherllo@iac.es; aloramas@iac.es
U.S. Department of EnergyUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; Fermi and Swift GI program [80NSSC17K0648, 80NSSC17K0314]
2021-08-03T12:40:30+00:00
sword
importub
filename=package.tar
17ad660a99214bfbe2700a1b85336c90
A. U. Abeysekara
Wystan Benbow
Ralph Bird
A. Brill
Robert Brose
J. H. Buckley
A. J. Chromey
M. K. Daniel
A. Falcone
J. P. Finley
L. Fortson
Amy Furniss
A. Gent
Gerald H. Gillanders
David Hanna
T. Hassan
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
Philip Kaaret
P. Kar
M. Kertzman
David Kieda
Maria Krause
F. Krennrich
S. Kumar
M. J. Lang
T. T. Y. Lin
Gernot Maier
P. Moriarty
Reshmi Mukherjee
R. A. Ong
Adam Nepomuk Otte
Nahee Park
A. Petrashyk
Martin Pohl
Elisa Pueschel
J. Quinn
K. Ragan
Gregory T. Richards
E. Roache
I. Sadeh
Marcos Santander
S. Schlenstedt
G. H. Sembroski
Iurii Sushch
J. Tyler
V. V. Vassiliev
S. P. Wakely
A. Weinstein
R. M. Wells
P. Wilcox
Alina Wilhelm
David A. Williams
T. J. Williamson
B. Zitzer
V. A. Acciari
S. Ansoldi
L. A. Antonelli
A. Arbet Engels
D. Baack
A. Babic
B. Banerjee
U. Barres de Almeida
J. A. Barrio
Josefa Becerra Gonzalez
Wlodek Bednarek
Elisa Bernardini
A. Berti
J. Besenrieder
W. Bhattacharyya
C. Bigongiari
A. Biland
O. Blanch
G. Bonnoli
G. Busetto
R. Carosi
G. Ceribella
S. Cikota
S. M. Colak
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
P. Da Vela
F. Dazzi
A. De Angelis
B. De Lotto
M. Delfino
J. Delgado
F. Di Pierro
E. Do Souto Espinera
A. Dominguez
D. Dominis Prester
D. Dorner
M. Doro
S. Einecke
D. Elsaesser
V. Fallah Ramazani
A. Fattorini
A. Fernandez-Barral
G. Ferrara
D. Fidalgo
L. Foffano
M. V. Fonseca
L. Font
C. Fruck
D. Galindo
S. Gallozzi
R. J. Garcia Lopez
M. Garczarczyk
S. Gasparyan
Markus Gaug
P. Giammaria
N. Godinovic
D. Guberman
D. Hadasch
A. Hahn
J. Herrera
J. Hoang
D. Hrupec
S. Inoue
K. Ishio
Y. Iwamura
H. Kubo
J. Kushida
D. Kuvezdic
A. Lamastra
D. Lelas
Francesco Leone
E. Lindfors
S. Lombardi
Francesco Longo
M. Lopez
A. Lopez-Oramas
B. Machado de Oliveira Fraga
C. Maggio
P. Majumdar
M. Makariev
M. Mallamaci
G. Maneva
M. Manganaro
K. Mannheim
L. Maraschi
M. Mariotti
M. Martinez
S. Masuda
D. Mazin
M. Minev
J. M. Miranda
R. Mirzoyan
E. Molina
A. Moralejo
V. Moreno
E. Moretti
Pere Munar-Adrover
V. Neustroev
Andrzej Niedzwiecki
Mireia Nievas Rosillo
C. Nigro
Kari Nilsson
D. Ninci
K. Nishijima
K. Noda
L. Nogues
M. Noethe
Simona Paiano
J. Palacio
D. Paneque
R. Paoletti
J. M. Paredes
G. Pedaletti
P. Penil
M. Peresano
M. Persic
P. G. Prada Moroni
E. Prandini
I. Puljak
J. R. Garcia
W. Rhode
Marc Ribo
J. Rico
C. Righi
A. Rugliancich
Lab Saha
Narek Sahakyan
T. Saito
K. Satalecka
T. Schweizer
J. Sitarek
I. Snidaric
D. Sobczynska
A. Somero
A. Stamerra
M. Strzys
T. Suric
Fabrizio Tavecchio
P. Temnikov
T. Terzic
M. Teshima
N. Torres-Alba
S. Tsujimoto
J. van Scherpenberg
G. Vanzo
M. Vazquez Acosta
I. Vovk
M. Will
D. Zaric
eng
uncontrolled
gamma rays: general
eng
uncontrolled
pulsars: individual (PSR J2032+4127, VER J2032+414, MAGIC J2032+4127)
eng
uncontrolled
stars: individual (MT91 213)
eng
uncontrolled
X-rays: binaries
Astronomie und zugeordnete Wissenschaften
Institut für Physik und Astronomie
Referiert
Import
Bronze Open-Access
44871
2016
2016
eng
12
594
article
EDP Sciences
Les Ulis
Veritas Collaboration
1
--
--
--
Very high energy outburst of Markarian 501 in May 2009
The very high energy (VHE; E > 100 GeV) blazar Markarian 501 was observed between April 17 and May 5 (MJD 54 938-54 956), 2009, as part of an extensive multiwavelength campaign from radio to VHE. Strong VHE yray activity was detected on May 1st with Whipple and VERITAS, when the flux (E > 400 GeV) increased to 10 times the preflare baseline flux (3.9 x 10(-11) ph cm(-2) s(-1)), reaching five times the flux of the Crab Nebula. This coincided with a decrease in the optical polarization and a rotation of the polarization angle by 15. This VHE flare showed a fast flux variation with an increase of a factor similar to 4 in 25 min, and a falling time of similar to 50 min. We present the observations of the quiescent state previous to the flare and of the high state after the flare, focusing on the flux and spectral variability from Whipple, VERITAS, Fermi-LAT, RXTE, and Swift combined with optical and radio data.
Physical chemistry, chemical physics : a journal of European Chemical Societies
10.1051/0004-6361/201628744
1432-0746
wos2016:2019
A76
WOS:000385832200085
Pichel, A (reprint author), Inst Astron & Fis Espacio, Casilla Correo 67,Sucursal 28,C1428ZAA, Buenos Aires, DF, Argentina., anapichel@iafe.uba.ar
US Department of Energy Office of Science; US National Science Foundation; Smithsonian Institution; NSERC in Canada; South African Research Chairs Initiative (SARChI) by National Research Foundation; Department of Science and Technology of South Africa
importub
2020-03-22T13:48:01+00:00
filename=package.tar
9eac71db8d99b6f78ad5d64f40931fa9
E. Aliu
S. Archambault
A. Archer
T. Arlen
T. Aune
Anna Barnacka
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
Markus Böttcher
A. Bouvier
M. Buchovecky
J. H. Buckley
V. Bugaev
J. V. Cardenzana
M. Cerruti
A. Cesarini
Xuhui Chen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
J. Dumm
J. D. Eisch
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
M. Hütten
Nils Hakansson
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
Y. Khassen
D. Kieda
M. Krause
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
M. Orr
A. N. Otte
D. Pandel
N. Park
V. Pelassa
J. S. Perkins
A. Pichel
Martin Pohl
A. Popkow
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
J. Rousselle
A. C. Rovero
D. B. Saxon
G. H. Sembroski
K. Shahinyan
F. Sheidaei
C. Skole
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
N. W. Todd
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
M. G. Baring
J. Becerra Gonzalez
A. N. Cillis
D. Horan
D. Paneque
eng
uncontrolled
BL Lacertae objects: individual: Mrk 501
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
Import
34657
2013
2013
eng
10
2
776
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
--
--
--
Discovery of a new tev Gamma-Ray source - VER J0521+211
We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov Telescope Array. These observations were motivated by the discovery of a cluster of >30 GeV photons in the first year of Fermi Large Area Telescope observations. VER J0521+211 is relatively bright at TeV energies, with a mean photon flux of (1.93 +/- 0.13(stat) +/- 0.78(sys)) x 10(-11) cm(-2) s(-1) above 0.2 TeV during the period of the VERITAS observations. The source is strongly variable on a daily timescale across all wavebands, from optical to TeV, with a peak flux corresponding to similar to 0.3 times the steady Crab Nebula flux at TeV energies. Follow-up observations in the optical and X-ray bands classify the newly discovered TeV source as a BL Lac-type blazar with uncertain redshift, although recent measurements suggest z = 0.108. VER J0521+211 exhibits all the defining properties of blazars in radio, optical, X-ray, and gamma-ray wavelengths.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/776/2/69
0004-637X
1538-4357
wos:2011-2013
69
WOS:000327216100006
Archambault, S (reprint author), McGill Univ, Dept Phys, 3600 Univ St, Montreal, PQ H3A 2T8, Canada., errando@astro.columbia.edu; jholder@physics.udel.edu; sfegan@llr.in2p3.fr; fortin@veritas.sao.arizona.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the UK; INAF in Italy; CNES in
France; NASA [NNX10AP66G, NNX12AJ30G, NNX10AF89G]; Russian Foundation
for Basic Research [11-02-00368, 12-02-33101]; Russian Academy of
Sciences; Dynasty Foundation; South African Department of Science and
Technology through the National Research Foundation under NRF SARChI
Chair [64789]; NASA-Fermi [NNX08AV67G, 11-Fermi11-0019, NNX09AU10G]
S. Archambault
T. Arlen
T. Aune
B. Behera
M. Beilicke
W. Benbow
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
A. Cesarini
L. Ciupik
M. P. Connolly
W. Cui
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
S. Kumar
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
J. Millis
P. Moriarty
R. Mukherjee
A. O'Faolain de Bhroithe
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
D. B. Saxon
G. H. Sembroski
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
Markus Boettcher
S. J. Fegan
P. Fortin
J. P. Halpern
Y. Y. Kovalev
M. L. Lister
J. Liu
A. B. Pushkarev
P. S. Smith
eng
uncontrolled
BL Lacertae objects: individual (VER J0521+211)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
36480
2011
2011
eng
7
2
742
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
--
--
--
Multiwavelenght observations of the previously unidentified blzar RX J0648.7+1516
We report on the VERITAS discovery of very high energy (VHE) gamma-ray emission above 200 GeV from the high-frequency-peaked BL Lac (HBL) object RX J0648.7+1516 (GB J0648+1516), associated with 1FGL J0648.8+1516. The photon spectrum above 200 GeV is fitted by a power law dN/dE = F-0(E/E-0)(-Gamma) with a photon index Gamma of 4.4 +/- 0.8(stat) +/- 0.3(syst) and a flux normalization F-0 of (2.3 +/- 0.5(stat) +/- 1.2(sys)) x 10(-11) TeV-1 cm(-2) s(-1) with E-0 = 300 GeV. No VHE variability is detected during VERITAS observations of RX J0648.7+1516 between 2010 March 4 and April 15. Following the VHE discovery, the optical identification and spectroscopic redshift were obtained using the Shane 3 m Telescope at the Lick Observatory, showing the unidentified object to be a BL Lac type with a redshift of z = 0.179. Broadband multiwavelength observations contemporaneous with the VERITAS exposure period can be used to subclassify the blazar as an HBL object, including data from the MDM observatory, Swift-UVOT, and X-Ray Telescope, and continuous monitoring at photon energies above 1 GeV from the Fermi Large Area Telescope (LAT). We find that in the absence of undetected, high-energy rapid variability, the one-zone synchrotron self-Compton (SSC) model overproduces the high-energy gamma-ray emission measured by the Fermi-LAT over 2.3 years. The spectral energy distribution can be parameterized satisfactorily with an external-Compton or lepto-hadronic model, which have two and six additional free parameters, respectively, compared to the one-zone SSC model.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/742/2/127
0004-637X
wos:2011-2013
127
WOS:000297211900067
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., afurniss@ucsc.edu; miki@ucolick.org; dpaneque@mppmu.mpg.de
US Department of Energy; NSERC in Canada; Science Foundation Ireland
(SFI ) [10/RFP/AST2748]; STFC in the UK; NASA [NNX10AF89G]; Fermi
[NNX09AU18G]; NSF [AST-0548180]; US National Science Foundation;
Smithsonian Institution
E. Aliu
T. Aune
M. Beilicke
W. Benbow
Markus Boettcher
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
A. Cannon
A. Cesarini
L. Ciupik
M. P. Connolly
W. Cui
G. Decerprit
R. Dickherber
C. Duke
M. Errando
A. Falcone
Q. Feng
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
B. Hivick
J. Holder
H. Huan
G. Hughes
C. M. Hui
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
G. H. Sembroski
C. Skole
A. W. Smith
D. Staszak
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
V. V. Vassiliev
S. P. Wakely
T. C. Weekes
A. Weinstein
D. A. Williams
B. Zitzer
S. Ciprini
M. Fumagalli
K. Kaplan
D. Paneque
J. X. Prochaska
eng
uncontrolled
BL Lacertae objects: individual (RX J0648.7+1516, 1FGL J0648.8+1516, VER J0648+152)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
35269
2013
2013
eng
13
2
762
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
--
--
--
Rapid TeV Gamma-Ray flaring of bl lacertae
We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 +/- 0.6) x 10(-6) photons m(-2) s(-1), roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 +/- 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 +/- 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/762/2/92
0004-637X
wos:2011-2013
92
WOS:000313008900026
Arlen, T (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA., cui@purdue.edu; qfeng@purdue.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; NASA [NNX08AV65G,
NNX08AV61G, NNX09AT99G, NNX11AQ03G, NNX08AW31G, NNX11A043G, NNX08AV67G];
NSF [AST-0907893, AST-0808050, AST-1109911]; Russian Foundation for
Basic Research [11-02-00368, 12-02-33101]; Physical Sciences Division of
the Russian Academy of Sciences; Dynasty Foundation; Academia Sinica;
Fermi Guest Investigator grants [NNX08AW56G, NNX09AU10G]; Academy of
Finland [212656, 210338, 121148]
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
J. H. Buckley
V. Bugaev
A. Cesarini
L. Ciupik
M. P. Connolly
W. Cui
R. Dickherber
J. Dumm
M. Errando
A. Falcone
S. Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
G. Maier
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
D. B. Saxon
M. Schroedter
G. H. Sembroski
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
K. Tsurusaki
A. Varlotta
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
S. G. Jorstad
N. R. MacDonald
A. P. Marscher
P. S. Smith
R. C. Walker
T. Hovatta
J. Richards
W. Max-Moerbeck
A. Readhead
M. L. Lister
Y. Y. Kovalev
A. B. Pushkarev
M. A. Gurwell
A. Lahteenmaki
E. Nieppola
M. Tornikoski
E. Jarvela
eng
uncontrolled
galaxies: active
eng
uncontrolled
galaxies: individual (BL Lacertae, VER J2202+422)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
35761
2012
2012
eng
7
1
754
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Veritas observations of the nova in V407 CYGNI
We report on very high energy (E > 100 GeV) gamma-ray observations of V407 Cygni, a symbiotic binary that underwent a nova outburst producing 0.1-10 GeV gamma rays during 2010 March 10-26. Observations were made with the Very Energetic Radiation Imaging Telescope Array System during 2010 March 19-26 at relatively large zenith angles due to the position of V407 Cyg. An improved reconstruction technique for large zenith angle observations is presented and used to analyze the data. We do not detect V407 Cygni and place a differential upper limit on the flux at 1.6 TeV of 2.3 x 10(-12) erg cm(-2) s(-1) (at the 95% confidence level). When considered jointly with data from Fermi-LAT, this result places limits on the acceleration of very high energy particles in the nova.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/754/1/77
0004-637X
wos:2011-2013
77
WOS:000306111800077
Aliu, E (reprint author), Columbia Univ, Dept Phys & Astron, Barnard Coll, New York, NY 10027 USA., daniel-d-gall@uiowa.edu; kazuma-tsurusaki@uiowa.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the UK
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
G. Decerprit
R. Dickherber
C. Duke
J. Dumm
Vikram V. Dwarkadas
M. Errando
A. Falcone
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
K. Lee
G. Maier
P. Majumdar
S. McArthur
A. McCann
J. Millis
P. Moriarty
R. Mukherjee
P. D. Nunez
R. A. Ong
M. Orr
A. N. Otte
D. Pandel
N. Park
J. S. Perkins
M. Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
C. Skole
A. W. Smith
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
gamma rays: general
eng
uncontrolled
novae, cataclysmic variables
eng
uncontrolled
white dwarfs
Institut für Physik und Astronomie
Referiert
35904
2012
2012
eng
6
2
750
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Disovery of high-energy and very high energy gamma-ray emission from the blazar RBS 0413
We report on the discovery of high-energy (HE; E > 0.1 GeV) and very high energy (VHE; E > 100 GeV) gamma-ray emission from the high-frequency-peaked BL Lac object RBS 0413. VERITAS, a ground-based gamma-ray observatory, detected VHE. rays from RBS 0413 with a statistical significance of 5.5 standard deviations (sigma) and a gamma-ray flux of (1.5 +/- 0.6(stat) +/- 0.7(syst)) x 10(-8) photons m(-2) s(-1) (similar to 1% of the Crab Nebula flux) above 250 GeV. The observed spectrum can be described by a power law with a photon index of 3.18 +/- 0.68(stat) +/- 0.30(syst). Contemporaneous observations with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope detected HE gamma rays from RBS 0413 with a (stat)istical significance of more than 9 sigma, a power-law photon index of 1.57 +/- 0.12(stat-0.12sys')(+0.11) and a gamma-ray flux between 300 MeV and 300 GeV of (1.64 +/- 0.43(stat-0.22sys)(+ 0.31)) x 10(-5) photons m(-2) s(-1). We present the results from Fermi-LAT and VERITAS, including a spectral energy distribution modeling of the gamma-ray, quasi-simultaneous X-ray (Swift-XRT), ultraviolet (Swift-UVOT), and R-band optical (MDM) data. We find that, if conditions close to equipartition are required, both the combined synchrotron self-Compton/external-Compton and the lepto-hadronic models are preferred over a pure synchrotron self-Compton model.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/750/2/94
0004-637X
wos:2011-2013
94
WOS:000303446500008
Aliu, E (reprint author), Columbia Univ, Dept Phys & Astron, Barnard Coll, New York, NY 10027 USA., gunessenturk@gmail.com; fortin@llr.in2p3.fr; deirdre@llr.in2p3.fr
US Department of Energy Office of Science; US National Science
Foundation; Smithsonian Institution; NASA; NSERC in Canada; Science
Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the UK
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
Markus Boettcher
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
P. Coppi
W. Cui
G. Decerprit
R. Dickherber
J. Dumm
Manel Errando
A. Falcone
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
K. Hawkins
J. Holder
H. Huan
G. Hughes
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
K. Lee
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
Reshmi Mukherjee
R. A. Ong
M. Orr
A. N. Otte
N. Palma
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
A. W. Smith
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
B. Zitzer
P. Fortin
D. Horan
eng
uncontrolled
BL Lacertae objects: individual (RBS 0413-VER J0319+187)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
36123
2012
2012
eng
7
2
746
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Veritas observations of day-scale flaring of M 87 in 2010 April
VERITAS has been monitoring the very-high-energy (VHE; > 100 GeV) gamma-ray activity of the radio galaxy M87 since 2007. During 2008, flaring activity on a timescale of a few days was observed with a peak flux of (0.70 +/- 0.16) x 10(-11) cm(-2) s(-1) at energies above 350 GeV. In 2010 April, VERITAS detected a flare from M 87 with peak flux of (2.71 +/- 0.68) x 10(-11) cm(-2) s(-1) for E > 350 GeV. The source was observed for six consecutive nights during the flare, resulting in a total of 21 hr of good-quality data. The most rapid flux variation occurred on the trailing edge of the flare with an exponential flux decay time of 0.90(-0.15)(+0.22) days. The shortest detected exponential rise time is three times as long, at 2.87(+1.65)(-0.99) days. The quality of the data sample is such that spectral analysis can be performed for three periods: rising flux, peak flux, and falling flux. The spectra obtained are consistent with power-law forms. The spectral index at the peak of the flare is equal to 2.19 +/- 0.07. There is some indication that the spectrum is softer in the falling phase of the flare than the peak phase, with a confidence level corresponding to 3.6 standard deviations. We discuss the implications of these results for the acceleration and cooling rates of VHE electrons in M 87 and the constraints they provide on the physical size of the emitting region.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/746/2/141
0004-637X
wos:2011-2013
141
WOS:000300406300027
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., cmhui@physics.utah.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland (SFI) [10/RFP/AST2748]; STFC in the UK
E. Aliu
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
M. Errando
A. Falcone
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
C. M. Hui
T. B. Humensky
A. Imran
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
S. LeBohec
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
P. D. Nunez
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
C. Skole
D. Staszak
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
B. Zitzer
eng
uncontrolled
galaxies: individual (M 87, VER J1230+123)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
35500
2012
2012
eng
13
2
760
article
IOP Publ. Ltd.
Bristol
1
--
--
--
SEARCH FOR A CORRELATION BETWEEN VERY-HIGH-ENERGY GAMMA RAYS AND GIANT RADIO PULSES IN THE CRAB PULSAR
We present the results of a joint observational campaign between the Green Bank radio telescope and the VERITAS gamma-ray telescope, which searched for a correlation between the emission of very-high-energy (VHE) gamma rays (E-gamma > 150 GeV) and giant radio pulses (GRPs) from the Crab pulsar at 8.9 GHz. A total of 15,366 GRPs were recorded during 11.6 hr of simultaneous observations, which were made across four nights in 2008 December and in 2009 November and December. We searched for an enhancement of the pulsed gamma-ray emission within time windows placed around the arrival time of the GRP events. In total, eight different time windows with durations ranging from 0.033 ms to 72 s were positioned at three different locations relative to the GRP to search for enhanced gamma-ray emission which lagged, led, or was concurrent with, the GRP event. Furthermore, we performed separate searches on main pulse GRPs and interpulse GRPs and on the most energetic GRPs in our data sample. No significant enhancement of pulsed VHE emission was found in any of the preformed searches. We set upper limits of 5-10 times the average VHE flux of the Crab pulsar on the flux simultaneous with interpulse GRPs on single-rotation-period timescales. On similar to 8 s timescales around interpulse GRPs, we set an upper limit of 2-3 times the average VHE flux. Within the framework of recent models for pulsed VHE emission from the Crab pulsar, the expected VHE-GRP emission correlations are below the derived limits.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/760/2/136
0004-637X
wos:2011-2013
136
WOS:000311217000040
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., mccann@kicp.uchicago.edu; nepomuk.otte@gmail.com; schroedter@veritas.sao.arizona.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the UK
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
J. Dumm
A. Falcone
S. Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
T. B. Humensky
P. Kaaret
N. Karlsson
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
S. LeBohec
K. Lee
M. Lyutikov
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
M. Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
D. B. Saxon
M. Schrödter
G. H. Sembroski
G. D. Sentuerk
A. W. Smith
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
S. Vincent
M. Vivier
R. G. Wagner
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
V. Kondratiev
eng
uncontrolled
rays: stars
eng
uncontrolled
pulsars: individual: B0531+21
Institut für Physik und Astronomie
Referiert
34931
2013
2013
eng
7
2
770
article
IOP Publ. Ltd.
Bristol
1
--
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--
Discovery of TeV Gamma-Ray emission toward supernova remnant SNR G78.2+2.1
We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0 degrees.23 +/- 0 degrees.03(stat-0 degrees.02sys)(+0 degrees.04) and its spectrum is well-characterized by a differential power law (dN/dE = N-0 x (E/TeV)-Gamma) with a photon index of Gamma = 2.37 +/- 0.14(stat) +/- 0.20(sys) and a flux normalization of N-0 = 1.5 +/- 0.2(stat) +/- 0.4(sys) x 10(-12) photon TeV-1 cm(-2) s(-1). This yields an integral flux of 5.2 +/- 0.8(stat) +/- 1.4(sys) x 10(-12) photon cm(-2) s(-1) above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/770/2/93
0004-637X
wos:2011-2013
93
WOS:000320111200011
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., amandajw@iastate.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; Science and Technology Facilities Council
in the UK; NASA [NNX11A086G]
E. tAliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
R. Bird
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
J. Dumm
Vikram V. Dwarkadas
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
E. V. Gotthelf
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
K. Lee
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
J. Millis
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
A. N. Otte
D. Pandel
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
Jens Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
C. Skole
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
acceleration of particles
eng
uncontrolled
cosmic rays
eng
uncontrolled
gamma rays: general
eng
uncontrolled
ISM: supernova remnants
Institut für Physik und Astronomie
Referiert
36660
2011
2011
eng
8
1
738
article
IOP Publ. Ltd.
Bristol
1
--
--
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VERITAS OBSERVATIONS OF THE TeV BINARY LS I+61 degrees 303 DURING 2008-2010
We present the results of observations of the TeV binary LS I + 61 degrees 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-based gamma-ray telescopes VERITAS and MAGIC have reported detections of TeV emission near the apastron phases of the binary orbit. The observations presented here show no strong evidence for TeV emission during these orbital phases; however, during observations taken in late 2010, significant emission was detected from the source close to the phase of superior conjunction (much closer to periastron passage) at a 5.6 standard deviation (5.6 sigma) post-trials significance. In total, between 2008 October and 2010 December a total exposure of 64.5 hr was accumulated with VERITAS on LS I + 61 degrees 303, resulting in an excess at the 3.3 sigma significance level for constant emission over the entire integrated data set. The flux upper limits derived for emission during the previously reliably active TeV phases (i.e., close to apastron) are less than 5% of the Crab Nebula flux in the same energy range. This result stands in apparent contrast to previous observations by both MAGIC and VERITAS which detected the source during these phases at 10% of the Crab Nebula flux. During the two year span of observations, a large amount of X-ray data were also accrued on LS I + 61 degrees 303 by the Swift X-ray Telescope and the Rossi X-ray Timing Explorer Proportional Counter Array. We find no evidence for a correlation between emission in the X-ray and TeV regimes during 20 directly overlapping observations. We also comment on data obtained contemporaneously by the Fermi Large Area Telescope.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/738/1/3
0004-637X
wos:2011-2013
3
WOS:000294015500003
Holder, J (reprint author), Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA., jholder@physics.udel.edu; awsmith@hep.anl.gov
U.S. Department of Energy; U.S. National Science Foundation; Smithsonian
Institution; NSERC in Canada; Science Foundation Ireland (SFI)
[10/RFP/AST2748]; STFC in the U.K; Argonne, a U.S. Department of Energy
Office of Science laboratory [DE-AC02-06CH11357]; NASA [NNX09AR91G]
V. A. Acciari
E. Aliu
T. Arlen
T. Aune
M. Beilicke
W. Benbow
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
M. Errando
A. Falcone
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
S. Griffin
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
G. Hughes
C. M. Hui
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
S. LeBohec
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Senturk
A. W. Smith
D. Staszak
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
B. Zitzer
eng
uncontrolled
binaries: general
eng
uncontrolled
gamma rays: general
eng
uncontrolled
X-rays: binaries
Institut für Physik und Astronomie
Referiert
36045
2012
2012
eng
12
6
85
article
American Physical Society
College Park
1
--
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VERITAS deep observations of the dwarf spheroidal galaxy Segue 1
The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report on the results of nearly 48 hours of good quality selected data, taken between January 2010 and May 2011. No significant gamma-ray emission is detected at the nominal position of Segue 1, and upper limits on the integrated flux are derived. According to recent studies, Segue 1 is the most dark matter-dominated dwarf spheroidal galaxy currently known. We derive stringent bounds on various annihilating and decaying dark matter particle models. The upper limits on the velocity-weighted annihilation cross-section are <sigma upsilon >(95%) (CL) less than or similar to 10(-23) cm(3) s(-1), improving our limits from previous observations of dwarf spheroidal galaxies by at least a factor of 2 for dark matter particle masses m(chi) greater than or similar to 300 GeV. The lower limits on the decay lifetime are at the level of tau(95%) (CL) greater than or similar to 10(24) s. Finally, we address the interpretation of the cosmic ray lepton anomalies measured by ATIC and PAMELA in terms of dark matter annihilation, and show that the VERITAS observations of Segue 1 disfavor such a scenario.
Physical review : D, Particles, fields, gravitation, and cosmology
10.1103/PhysRevD.85.062001
1550-7998
wos:2011-2013
062001
WOS:000301117000003
Vivier, M (reprint author), Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA., mvivier@bartol.udel.edu
US Department of Energy Office of Science; US National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the United Kingdom
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
J. L. Christiansen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
G. Decerprit
R. Dickherber
J. Dumm
M. Errando
A. Falcone
Q. Feng
F. Ferrer
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
K. Lee
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
C. Skole
A. W. Smith
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
R. G. Wagner
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
B. Zitzer
Institut für Physik und Astronomie
Referiert
36552
2011
2011
eng
69
72
4
6052
334
article
American Assoc. for the Advancement of Science
Washington
VERITAS Collaboration
1
--
--
--
Detection of pulsed Gamma Rays Above 100 GeV from the Crab Pulsar
We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.
Science
10.1126/science.1208192
0036-8075
wos:2011-2013
WOS:000295580300040
McCann, A (reprint author), McGill Univ, Dept Phys, 3600 Univ St, Montreal, PQ H3A 2T8, Canada., mccann@hep.physics.mcgill.ca; nepomuk.otte@gmail.com; schroedter@veritas.sao.arizona.edu
U.S. Department of Energy; NSF; Smithsonian Institution; Natural
Sciences and Engineering Research Council of Canada; Science Foundation
Ireland (SFI) [10/RFP/AST2748]; Science and Technology Facilities
Council in the United Kingdom; Alexander von Humboldt Foundation
E. Aliu
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
J. L. Christiansen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
M. Errando
A. Falcone
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
K. Gibbs
G. H. Gillanders
S. Godambe
S. Griffin
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
C. M. Hui
T. B. Humensky
A. Imran
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
M. Lyutikov
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
M. McCutcheon
P. Moriarty
R. Mukherjee
P. Nunez
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
F. Pizlo
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
A. W. Smith
D. Staszak
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
B. Zitzer
Institut für Physik und Astronomie
Referiert
38010
2014
2014
eng
9
1
783
article
IOP Publ. Ltd.
Bristol
1
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--
--
Observations of the unidentified gamm-ray source TeV J2032+4130 BY Veritas
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/783/1/16
0004-637X
1538-4357
wos:2014
16
WOS:000334919600016
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., gareth.hughes@desy.de; pratik.majumdar@saha.ac.in
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.; Young Investigators
Program of the Helmholtz Association; NASA [NNX09AC84G, NNX09AC81G]
E. Aliu
T. Aune
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
J. H. Buckley
V. Bugaev
J. V. Cardenzana
M. Cerruti
X. Chen
L. Ciupik
M. P. Connolly
W. Cui
C. Duke
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
Oleg Kargaltsev
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
A. McCann
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
D. Pandel
J. S. Perkins
Manuela Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
C. Skole
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. V. Tucci
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
gamma rays: general
eng
uncontrolled
pulsars: individual (PSR J2032+4127)
Institut für Physik und Astronomie
Referiert
35214
2013
2013
eng
9
1
764
article
IOP PUBLISHING LTD
BRISTOL
1
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--
DISCOVERY OF TeV GAMMA-RAY EMISSION FROM CTA 1 BY VERITAS
We report the discovery of TeV gamma-ray emission coincident with the shell-type radio supernova remnant (SNR) CTA 1 using the VERITAS gamma-ray observatory. The source, VER J0006+729, was detected as a 6.5 standard deviation excess over background and shows an extended morphology, approximated by a two-dimensional Gaussian of semimajor (semiminor) axis 0.degrees 30 (0.degrees 24) and a centroid 5’ from the Fermi gamma-ray pulsar PSR J0007+7303 and its X-ray pulsar wind nebula (PWN). The photon spectrum is well described by a power-law dN/dE = N-0(E/3 TeV)(-Gamma), with a differential spectral index of Gamma = 2.2 +/- 0.2(stat) +/- 0.3(sys), and normalization N-0 = (9.1 +/- 1.3(stat) +/- 1.7(sys)) x 10(-14) cm(-2) s(-1) TeV-1. The integral flux, F-gamma = 4.0 x 10(-12) erg cm(-2) s(-1) above 1 TeV, corresponds to 0.2% of the pulsar spin-down power at 1.4 kpc. The energetics, colocation with the SNR, and the relatively small extent of the TeV emission strongly argue for the PWN origin of the TeV photons. We consider the origin of the TeV emission in CTA 1.
ASTROPHYSICAL JOURNAL
10.1088/0004-637X/764/1/38
0004-637X
wos:2011-2013
38
WOS:000314335200038
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA.
, smcarthur@ulysses.uchicago.edu; muk@astro.columbia.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.; National Science
Foundation [AST0908733]; NASA [NAS8-03060]
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
J. H. Buckley
V. Bugaev
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
J. Dumm
Vikram V. Dwarkadas
M. Errando
A. Falcone
S. Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
E. V. Gotthelf
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
O. Kargaltsev
N. Karlsson
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
K. Lee
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
A. O&rsquo de Bhroithe
Faolain
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
M. Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
M. Roberts
D. B. Saxon
M. Schroedter
G. H. Sembroski
P. Slane
A. W. Smith
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
gamma-rays: stars
eng
uncontrolled
pulsars: individual (PSR J0007+7303)
eng
uncontrolled
supernovae: individual (G119.5+10.2)
eng
uncontrolled
X-rays: individual (RX J0007.0+7303)
34509
2013
2013
eng
9
2
779
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
--
--
--
Long term observations of B2 1215+30 with veritas
We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHEs; E > 100 GeV) by VERITAS with a significance of 8.9s and showed clear variability on timescales larger than months. In 2011, the source was found to be in a relatively bright state and a power-law fit to the differential photon spectrum yields a spectral index of 3.6 +/- 0.4(stat) +/- 0.3(syst) with an integral flux above 200 GeV of (8.0 +/- 0.9(stat) +/- 3.2(syst)) x 10(-12) cm(-2) s(-1). No short term variability could be detected during the bright state in 2011. Multi-wavelength data were obtained contemporaneously with the VERITAS observations in 2011 and cover optical (Super-LOTIS, MDM, Swift/UVOT), X-ray (Swift/XRT), and gamma-ray (Fermi-LAT) frequencies. These were used to construct the spectral energy distribution (SED) of B2 1215+30. A one-zone leptonic model is used to model the blazar emission and the results are compared to those of MAGIC from early 2011 and other VERITAS-detected blazars. The SED can be reproduced well with model parameters typical for VHE-detected BL Lac objects.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/779/2/92
0004-637X
1538-4357
wos:2011-2013
92
WOS:000328187200002
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., heike.prokoph@desy.de
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.; NASA Swift Guest
Investigator program [NNX12AJ12G]; Helmholtz Association; South African
Research Chairs Initiative of the Department of Science and Technology;
National Research Foundation of South Africa; NASA through Hubble
Fellowship grant [HF-51305.01-A]; Space Telescope Science Institute;
NASA [NAS 5-26555]
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
A. Cesarini
L. Ciupik
M. P. Connolly
W. Cui
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
L. Gerard
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
D. Nieto
A. O'Faolain De Bhroithe
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
D. B. Saxon
G. H. Sembroski
C. Skole
A. W. Smith
M. Soares-Furtado
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
Markus Böttcher
M. Fumagalli
J. Jadhav
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual (B2 1215+30, VER J1217+301)
34727
2013
2013
eng
8
1
775
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Multiwavelenght observations and modeling of 1ES 1959+650 in a low flux state
We report on the VERITAS observations of the high-frequency peaked BL Lac object 1ES 1959+650 in the period 2007-2011. This source is detected at TeV energies by VERITAS at 16.4 standard deviation (sigma) significance in 7.6 hr of observation in a low flux state. A multiwavelength spectral energy distribution (SED) is constructed from contemporaneous data from VERITAS, Fermi-LAT, RXTE PCA, and Swift UVOT. Swift XRT data is not included in the SED due to a lack of simultaneous observations with VERITAS. In contrast to the orphan gamma-ray flare exhibited by this source in 2002, the X-ray flux of the source is found to vary by an order of magnitude, while other energy regimes exhibit less variable emission. A quasi-equilibrium synchrotron self-Compton model with an additional external radiation field is used to describe three SEDs corresponding to the lowest, highest, and average X-ray states. The variation in the X-ray spectrum is modeled by changing the electron injection spectral index, with minor adjustments of the kinetic luminosity in electrons. This scenario produces small-scale flux variability of the order of less than or similar to 2 in the high energy (E > 1MeV) and very high energy (E > 100 GeV) gamma-ray regimes, which is corroborated by the Fermi-LAT, VERITAS, and Whipple 10 m telescope light curves.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/775/1/3
0004-637X
wos:2011-2013
3
WOS:000324615800003
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA.
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NARC'S in Canada; Science
Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.; Irish
Research Council "Embark Initiative"
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
R. Bird
Markus Boettcher
A. Bouvier
V. Bugaev
K. Byrum
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
D. B. Saxon
M. Schroedter
G. H. Sembroski
C. Skole
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. Tyler
A. Varlotta
V. V. Vassiliev
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual (1ES 1959+650=VER J1959+651)
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
36916
2011
2011
eng
6
2
730
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Discovery of OF TeV Gamma-Ray emission from tycho's supernova remnant
We report the discovery of TeV gamma-ray emission from the Type Ia supernova remnant (SNR) G120.1+1.4, known as Tycho's SNR. Observations performed in the period 2008-2010 with the VERITAS ground-based gamma-ray observatory reveal weak emission coming from the direction of the remnant, compatible with a point source located at 00(h)25(m)27(s).0, +64 degrees 10'50 '' (J2000). The TeV photon spectrum measured by VERITAS can be described with a power law dN/dE = C(E/3.42 TeV)(-Gamma) with Gamma = 1.95 +/- 0.51(stat) +/- 0.30(sys) and C = (1.55 +/- 0.43(stat) +/- 0.47(sys)) x 10(-14) cm(-2) s(-1) TeV-1. The integral flux above 1 TeV corresponds to similar to 0.9% of the steady Crab Nebula emission above the same energy, making it one of the weakest sources yet detected in TeV gamma rays. We present both leptonic and hadronic models that can describe the data. The lowest magnetic field allowed in these models is similar to 80 mu G, which may be interpreted as evidence for magnetic field amplification.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.1088/2041-8205/730/2/L20
2041-8205
wos:2011-2013
L20
WOS:000293125600008
Acciari, VA (reprint author), Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA., dbsaxon@udel.edu; wakely@uchicago.edu
U.S. Department of Energy; U.S. National Science Foundation; Smithsonian
Institution; Natural Sciences and Engineering Research Council (NSERC)
in Canada; Science Foundation Ireland [SFI 10/RFP/AST2748]; Science and
Technology Facilities Council in the UK; NSERC; NASA [NNX08AZ86G]
V. A. Acciari
E. Aliu
T. Arlen
T. Aune
M. Beilicke
W. Benbow
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
W. Cui
R. Dickherber
C. Duke
M. Errando
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
S. Griffin
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
J. P. Hughes
C. M. Hui
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
S. LeBohec
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
R. A. Ong
M. Orr
A. N. Otte
D. Pandel
N. H. Park
J. S. Perkins
Martin Pohl
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. Demet Senturk
P. Slane
A. W. Smith
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
M. Wood
B. Zitzer
eng
uncontrolled
gamma rays: general
eng
uncontrolled
ISM: individual objects (G120.1+01.4, Tycho=VER J0025+641)
Institut für Physik und Astronomie
Referiert
37773
2014
2014
eng
10
1
788
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Spatially resolving the very high energy emission from MRGO J2019+37 wih veritas
We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended (similar to 2 degrees) unidentified Milagro source is located toward the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint, point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the 0.65-10 TeV energy range by a power-law model with photon index 2.3 +/- 0.4. VER J2019+378 is a bright extended (similar to 1 degrees) source that likely accounts for the bulk of the Milagro emission and is notably coincident with PSR J2021+3651 and the star formation region Sh 2-104. Its spectrum in the range 1-30 TeV is well fit with a power-law model of photon index 1.75 +/- 0.3, among the hardest values measured in the VHE band, comparable to that observed near Vela-X. We explore the unusual spectrum and morphology in the radio and X-ray bands to constrain possible emission mechanisms for this source.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/788/1/78
0004-637X
1538-4357
wos:2014
78
WOS:000337095200078
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., ealiu@astro.columbia.edu; nahee@uchicago.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U. K; ESA Member States and
NASA; Natural Sciences and Engineering Research Council
E. Aliu
T. Aune
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
J. Dumm
Vikram V. Dwarkadas
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
E. V. Gotthelf
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
O. Kargaltsev
M. Kertzman
Y. Khassen
D. Kieda
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
S. McArthur
A. McCann
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
D. Pandel
N. Park
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
M. Roberts
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. Vincent
S. P. Wakely
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
gamma rays : stars
eng
uncontrolled
pulsars : individual (PSR J2021+3651)
eng
uncontrolled
supernovae : individual (CTB 87)
Institut für Physik und Astronomie
Referiert
38057
2014
2014
eng
12
1
782
article
IOP Publ. Ltd.
Bristol
1
--
--
--
A three-year multi-wavelenght study of the very-high-energy gamma-ray Blazar 1ES 0229+200
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/782/1/13
0004-637X
1538-4357
wos:2014
13
WOS:000331848200013
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., mcerruti@cfa.harvard.edu; jeremy.s.perkins@nasa.gov
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; National Aeronautics and
Space Administration
E. Aliu
S. Archambault
T. Arlen
T. Aune
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
C. Duke
J. Dumm
M. Errando
A. Falcone
S. Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
M. Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
A. Zajczyk
B. Zitzer
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual (1ES 0229+200, VER J0232+202)
eng
uncontrolled
diffuse radiation
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: general
eng
uncontrolled
magnetic fields
Institut für Physik und Astronomie
Referiert
39244
2015
2015
eng
9
1
799
article
IOP Publ. Ltd.
Bristol
1
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--
--
Veritas observations of the BL LAC OBJECT PG 1553+113
We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560 GeV, is well described by a power law with a spectral index of 4.33 +/- 0.09. The time-averaged integral flux above 200 GeV measured for this period was (1.69 +/- 0.06) x 10(-11) photons cm(-2) s(-1), corresponding to 6.9% of the Crab Nebula flux. We also present the combined gamma-ray spectrum from the Fermi Large Area Telescope and VERITAS covering an energy range from 100 MeV to 560 GeV. The data are well fit by a power law with an exponential cutoff at 101.9 +/- 3.2 GeV. The origin of the cutoff could be intrinsic to PG 1553+113 or be due to the gamma-ray opacity of our universe through pair production off the extragalactic background light (EBL). Given lower limits to the redshift of z > 0.395 based on optical/UV observations of PG 1553+113, the cutoff would be dominated by EBL absorption. Conversely, the small statistical uncertainties of the VERITAS energy spectrum have allowed us to provide a robust upper limit on the redshift of PG 1553+113 of z <= 0.62. A strongly elevated mean flux of (2.50 +/- 0.14) x10(-11) photons cm(-2) s(-1) (10.3% of the Crab Nebula flux) was observed during 2012, with the daily flux reaching as high as (4.44 +/- 0.71) x10(-11) photons cm(-2) s(-1) (18.3% of the Crab Nebula flux) on MJD 56048. The light curve measured during the 2012 observing season is marginally inconsistent with a steady flux, giving a chi(2) probability for a steady flux of 0.03%.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/799/1/7
0004-637X
1538-4357
wos:2015
7
WOS:000348214500007
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA.
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.
E. Aliu
A. Archer
T. Aune
Anna Barnacka
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
Wei Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
Nils Hakansson
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
S. Kumar
M. J. Lang
A. Madhavan
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
Daniel Nieto
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. P. Wakely
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
BL Lacertae objects: general
Institut für Physik und Astronomie
Referiert
35614
2012
2012
eng
14
2
757
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Constraints on cosmic rays, magnetic fields, and dark matter fromgamma-ray observations of the coma cluster of galaxies with veritas and fermi
Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on the order of (2-5) x 10(-8) photonsm(-2) s(-1) (VERITAS, >220 GeV) and similar to 2 x 10(-6) photonsm(-2) s(-1) (Fermi, 1-3GeV), respectively. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be < 16% from VERITAS data and <1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Assuming that the radio-emitting electrons of the Coma halo result from hadronic CR interactions, the observations imply a lower limit on the central magnetic field in Coma of similar to(2-5.5) mu G, depending on the radial magnetic field profile and on the gamma-ray spectral index. Since these values are below those inferred by Faraday rotation measurements in Coma (for most of the parameter space), this renders the hadronic model a very plausible explanation of the Coma radio halo. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, <sigma nu >.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/757/2/123
0004-637X
wos:2011-2013
123
WOS:000309108500016
Arlen, T (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA., pohlmadq@gmail.com; christoph.pfrommer@h-its.org
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; National Aeronautics and
Space Administration; Department of Energy in the United States;
Commissariat a l'Energie Atomique; Centre National de la Recherche
Scientifique/Institut National de Physique Nucleaire et de Physique des
Particules in France; Agenzia Spaziale Italiana; Istituto Nazionale di
Fisica Nucleare in Italy; Ministry of Education, Culture, Sports,
Science and Technology (MEXT); High Energy Accelerator Research
Organization (KEK); Japan Aerospace Exploration Agency (JAXA) in Japan;
K. A. Wallenberg Foundation; Swedish Research Council; Swedish National
Space Board in Sweden; Istituto Nazionale di Astrofisica in Italy;
Centre National d'Etudes Spatiales in France; Klaus Tschira Foundation;
NSF [AST-0908480]
T. Arlen
T. Aune
M. Beilicke
W. Benbow
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
J. Dumm
A. Falcone
S. Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
G. Gyuk
J. Holder
H. Huan
G. Hughes
T. B. Humensky
A. Imran
P. Kaaret
N. Karlsson
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
K. Lee
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
C. Skole
A. W. Smith
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
M. Vivier
S. P. Wakely
J. E. Ward
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
C. Pfrommer
A. Pinzke
eng
uncontrolled
cosmic rays
eng
uncontrolled
dark matter
eng
uncontrolled
galaxies: clusters: general
eng
uncontrolled
galaxies: clusters: individual (Coma (ACO 1656))
eng
uncontrolled
gamma rays: galaxies: clusters
eng
uncontrolled
magnetic fields
Institut für Physik und Astronomie
Referiert
36437
2011
2011
eng
10
1
743
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Veritas observations of gamma-ray bursts detected by swift
We present the results of 16 Swift-triggered Gamma-ray burst (GRB) follow-up observations taken with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) telescope array from 2007 January to 2009 June. The median energy threshold and response time of these observations were 260 GeV and 320 s, respectively. Observations had an average duration of 90 minutes. Each burst is analyzed independently in two modes: over the whole duration of the observations and again over a shorter timescale determined by the maximum VERITAS sensitivity to a burst with a t(-1.5) time profile. This temporal model is characteristic of GRB afterglows with high-energy, long-lived emission that have been detected by the Large Area Telescope on board the Fermi satellite. No significant very high energy (VHE) gamma-ray emission was detected and upper limits above the VERITAS threshold energy are calculated. The VERITAS upper limits are corrected for gamma-ray extinction by the extragalactic background light and interpreted in the context of the keV emission detected by Swift. For some bursts the VHE emission must have less power than the keV emission, placing constraints on inverse Compton models of VHE emission.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/743/1/62
0004-637X
wos:2011-2013
62
WOS:000297408300062
Aune, T (reprint author), Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA.
US Department of Energy; US National Science Foundation; Smithsonian
Institution; NSERC in Canada; Science Foundation Ireland [SFI
10/RFP/AST2748]; STFC in the UK; NASA [NNX09AR06G]
V. A. Acciari
E. Aliu
T. Arlen
T. Aune
M. Beilicke
W. Benbow
S. M. Bradbury
J. H. Buckley
V. Bugaev
K. Byrum
A. Cannon
A. Cesarini
J. L. Christiansen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
C. Duke
M. Errando
A. Falcone
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
G. Hughes
C. M. Hui
T. B. Humensky
D. J. Jackson
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
S. McArthur
A. McCann
P. Moriarty
M. D. Newbold
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
A. W. Smith
D. Staszak
S. P. Swordy
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
M. Wood
eng
uncontrolled
astroparticle physics
eng
uncontrolled
gamma-ray burst: general
Institut für Physik und Astronomie
Referiert
37935
2014
2014
eng
8
1
785
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration, Fermi LAT Collaboration
1
--
--
--
Deep broadband observations of the distant gamma-ray blazar PKS 1424+240
We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z >= 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 +/- 0.3) x 10(-7) photons m(-2) s(-1) above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02 +/- 0.08) x 10-7 photons m(-2) s(-1) above 120 GeV. The measured differential very high energy (VHE; E >= 100 GeV) spectral indices are Gamma = 3.8 +/- 0.3, 4.3 +/- 0.6 and 4.5 +/- 0.2 in 2009, 2011, and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than tau = 2, where it is postulated that any variability would be small and occur on timescales longer than a year if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.1088/2041-8205/785/1/L16
2041-8205
2041-8213
wos:2014
L16
WOS:000334345000016
Archambault, S (reprint author), McGill Univ, Dept Phys, 3600 Univ St, Montreal, PQ H3A 2T8, Canada., amy.furniss@gmail.com
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the UK; NASA through the Space
Telescope Science Institute [HST-GO-12863]; NASA [NAS 5-26555]; INAF in
Italy; CNES in France
S. Archambault
T. Aune
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
Jonathan Biteau
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
Wei Cui
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
S. Kumar
M. J. Lang
A. S. Madhavan
G. Maier
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
Daniel Nieto
R. A. Ong
A. N. Otte
N. Park
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
Margit Ackermann
M. Ajello
A. Albert
L. Baldini
D. Bastieri
R. Bellazzini
E. Bissaldi
Johan Bregeon
R. Buehler
S. Buson
G. A. Caliandro
R. A. Cameron
P. A. Caraveo
E. Cavazzuti
E. Charles
J. Chiang
S. Ciprini
R. Claus
S. Cutini
A. de Angelis
F. de Palma
C. D. Dermer
S. W. Digel
L. Di Venere
P. S. Drell
C. Favuzzi
A. Franckowiak
P. Fusco
F. Gargano
D. Gasparrini
N. Giglietto
F. Giordano
M. Giroletti
I. A. Grenier
S. Guiriec
T. Jogler
M. Kuss
S. Larsson
L. Latronico
F. Longo
F. Loparco
P. Lubrano
G. M. Madejski
M. Mayer
Mario Nicola Mazziotta
P. F. Michelson
T. Mizuno
M. E. Monzani
Aldo Morselli
S. Murgia
E. Nuss
T. Ohsugi
J. F. Ormes
D. Paneque
J. S. Perkins
F. Piron
G. Pivato
S. Raino
M. Razzano
A. Reimer
Olaf Reimer
S. Ritz
M. Schaal
C. Sgro
E. J. Siskind
P. Spinelli
H. Takahashi
L. Tibaldo
M. Tinivella
E. Troja
G. Vianello
M. Werner
M. Wood
eng
uncontrolled
BL Lacertae objects: individual (PKS 1424+240)-cosmic background radiation
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
37769
2014
2014
eng
9
2
788
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Test of models of the cosmic infrared background with multiwavelength observations of the blazar 1ES 1218+30.4 IN 2009
We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and gamma-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, > 100 GeV) observations, as well as contemporaneous optical and Fermi observations. The 1ES 1218+30.4 broadband energy spectrum-the first with simultaneous X-ray and VHE gamma-ray energy spectra-is of particular interest as the source is located at a high cosmological redshift for a VHE source (z = 0.182), leading to strong absorption of VHE gamma rays by photons from the optical/infrared extragalactic background light (EBL) via gamma VHE +gamma EBL -> e(+) e(-)pair-creation processes. We model the data with a one-zone synchrotron self-Compton (SSC) emission model and with the extragalactic absorption predicted by several recent EBL models. We find that the observations are consistent with the SSC scenario and all the EBL models considered in this work. We discuss observational and theoretical avenues to improve on the EBL constraints.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/788/2/158
0004-637X
1538-4357
wos:2014
158
WOS:000337466200061
Archambault, S (reprint author), McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada.
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
R. Bird
Markus Boettcher
A. Bouvier
J. H. Buckley
V. Bugaev
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
L. Fortson
A. Furniss
N. Galante
D. Gall
A. III. Garson
G. H. Gillanders
S. Griffin
J. Grube
C. Gusbar
G. Gyuk
D. Hanna
J. Holder
G. Hughes
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
A. Lamerato
M. J. Lang
K. Li
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
P. Roustazadeh
D. B. Saxon
G. H. Sembroski
G. D. Senturk
C. Skole
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual (1ES1218+30.4)
eng
uncontrolled
cosmic background radiation
eng
uncontrolled
diffuse radiation
eng
uncontrolled
galaxies: jets
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
45182
2016
2016
eng
2550
2557
8
459
article
Oxford Univ. Press
Oxford
1
--
--
--
VERITAS and multiwavelength observations of the BL Lacertae object 1ES 1741+196
We present results from multiwavelength observations of the BL Lacertae object 1ES 1741 + 196, including results in the very high energy gamma-ray regime using the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is well modelled by a power law with a spectral index of 2.7 +/- 0.7(stat) +/- 0.2(syst). The integral flux above 180 GeV is (3.9 +/- 0.8(stat) +/- 1.0(syst)) x 10(-8) m(-2) s(-1), corresponding to 1.6 per cent of the Crab nebula flux on average. The multiwavelength spectral energy distribution of the source suggests that 1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The observations analysed in this paper extend over a period of six years, during which time no strong flares were observed in any band. This analysis is therefore one of the few characterizations of a blazar in a non-flaring state.
Monthly notices of the Royal Astronomical Society
10.1093/mnras/stw664
0035-8711
1365-2966
wos2016:2019
WOS:000379840900022
Christiansen, JL (reprint author), Calif Polytech State Univ San Luis Obispo, Dept Phys, San Luis Obispo, CA 94307 USA., jlchrist@calpoly.edu; elisa.pueschel@ucd.ie
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada; Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231]; Marie Curie Intra-European Fellowship within 7th European Community
importub
2020-03-22T16:23:01+00:00
filename=package.tar
1f02f9e38601f06267b750f74fe6efa2
A. U. Abeysekara
S. Archambault
A. Archer
W. Benbow
R. Bird
Jonathan Biteau
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
J. L. Christiansen
L. Ciupik
M. P. Connolly
W. Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
M. Errando
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
A. Flinders
P. Fortin
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
M. Huetten
D. Hanna
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
M. J. Lang
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
V. Pelassa
A. Petrashyk
D. Petry
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
G. Ratliff
L. C. Reyes
P. T. Reynolds
K. Reynolds
G. T. Richards
E. Roache
C. Rulten
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
astroparticle physics
eng
uncontrolled
relativistic processes
eng
uncontrolled
galaxies: individual: 1ES 1741+196=VER J1744+195
Institut für Physik und Astronomie
Referiert
Import
35522
2012
2012
eng
13
2
759
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
--
--
--
Veritas observations of six bright, hard-spectrum fermi-lat blazars
We report on VERITAS very high energy (VHE; E >= 100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band, taking gamma-ray absorption by the extragalactic background light into account. This allowed the selection of six bright, hard-spectrum blazars that were good candidate TeV emitters. Spectroscopic redshift measurements were attempted with the Keck Telescope for the targets without Sloan Digital Sky Survey spectroscopic data. No VHE emission is detected during the observations of the six sources described here. Corresponding TeV upper limits are presented, along with contemporaneous Fermi observations and non-concurrent Swift UVOT and X-Ray Telescope data. The blazar broadband spectral energy distributions (SEDs) are assembled and modeled with a single-zone synchrotron self-Compton model. The SED built for each of the six blazars shows a synchrotron peak bordering between the intermediate-and high-spectrum-peak classifications, with four of the six resulting in particle-dominated emission regions.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/759/2/102
0004-637X
wos:2011-2013
102
WOS:000310911300025
Furniss, A (reprint author), Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA., afurniss@ucsc.edu; pafortin@cfa.harvard.edu; deirdre@llr.in2p3.fr
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; NSF [AST-0548180]; Alfred
P. Sloan Foundation; U.S. Department of Energy; National Aeronautics and
Space Administration; Japanese Monbukagakusho; Max Planck Society;
Higher Education Funding Council for England; Istituto Nazionale di
Astrofisica in Italy; Centre National d'Etudes Spatiales in France
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
Markus Boettcher
A. Bouvier
J. H. Buckley
V. Bugaev
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
C. Duke
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
P. Kaaret
N. Karlsson
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
K. Lee
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
D. B. Saxon
G. H. Sembroski
D. Staszak
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
V. V. Vassiliev
S. Vincent
M. Vivier
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
P. Fortin
D. Horan
M. Fumagalli
K. Kaplan
J. X. Prochaska
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
35697
2012
2012
eng
7
2
755
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Multiwavelength observations of the AGN 1ES 0414+009 with veritas, FERMI-LAT, SWIFT-XRT, AND MDM
We present observations of the BL Lac object 1ES 0414+009 in the >200 GeV gamma-ray band by the VERITAS array of Cherenkov telescopes. 1ES 0414+009 was observed by VERITAS between 2008 January and 2011 February, resulting in 56.2 hr of good quality pointed observations. These observations resulted in a detection of 822 events from the source corresponding to a statistical significance of 6.4 standard deviations (6.4 sigma) above the background. The source flux, showing no evidence for variability, is measured as (5.2 +/- 1.1(stat) +/- 2.6(sys)) x 10(-12) photons cm(-2) s(-1) above 200 GeV, equivalent to approximately 2% of the Crab Nebula flux above this energy. The differential photon spectrum from 230 GeV to 850 GeV is well fit by a power law with a photon index of Gamma = 3.4 +/- 0.5(stat) +/- 0.3(sys) and a flux normalization of (1.6 +/- 0.3(stat) +/- 0.8(sys)) x 10(-11) photons cm(-2) s(-1) at 300 GeV. We also present multiwavelength results taken in the optical (MDM), x-ray (Swift-XRT), and GeV (Fermi-LAT) bands and use these results to construct a broadband spectral energy distribution (SED). Modeling of this SED indicates that homogenous one-zone leptonic scenarios are not adequate to describe emission from the system, with a lepto-hadronic model providing a better fit to the data.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/755/2/118
0004-637X
wos:2011-2013
118
WOS:000307791400035
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., aw.smith@utah.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.
E. Aliu
S. Archambault
T. Arlen
T. Aune
M. Beilicke
W. Benbow
Markus Boettcher
A. Bouvier
V. Bugaev
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
J. Dumm
M. Errando
A. Falcone
Stefania Federici
Q. Feng
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
C. M. Hui
A. Imran
O. Jameil
P. Kaaret
N. Karlsson
M. Kertzman
J. Kerr
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
K. Lee
A. S. Madhavan
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
T. Nelson
A. O'Faolain de Bhroithe
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
J. Quinn
K. Ragan
P. T. Reynolds
E. Roache
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
G. D. Sentuerk
A. W. Smith
D. Staszak
M. Stroh
Igor O. Telezhinsky
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
A. Varlotta
V. V. Vassiliev
M. Vivier
S. P. Wakely
J. E. Ward
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
BL Lacertae objects: individual (1ES 0414+009, ERJ0416+011)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
45685
2016
2016
eng
6
817
article
IOP Publ. Ltd.
Bristol
1
--
--
--
EXCEPTIONALLY BRIGHT TEV FLARES FROM THE BINARY LS I+61 degrees 303
The TeV binary system LS I +61 degrees 303 is known for its regular, non-thermal emission pattern that traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (> 300 GeV). In this article, VERITAS observations of LS I + 61 degrees. 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. This is the brightest such activity from this source ever seen in the TeV regime. The strong outbursts have rise and fall times of less than a day. The short timescale of the flares, in conjunction with the observation of 10 TeV photons from LS I + 61 degrees 303 during the flares, provides constraints on the properties of the accelerator in the source.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.3847/2041-8205/817/1/L7
2041-8205
2041-8213
wos2016:2019
L7
WOS:000369370900007
de Bhroithe, AO (reprint author), DESY, Platanenallee 6, D-15738 Zeuthen, Germany., anna.ofaolain.de.bhroithe@desy.de
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada; Helmholtz Association; Fermi Cycle 7 Guest Investigator Program [NNH13ZDA001N]
importub
2020-03-22T20:36:01+00:00
filename=package.tar
592e91ffb44aae7a1179adfd949e7e2d
S. Archambault
A. Archer
T. Aune
Anna Barnacka
W. Benbow
R. Bird
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
A. Flinders
P. Fortin
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
M. Huetten
Nils Hakansson
D. Hanna
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
Y. Khassen
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
D. Pandel
N. Park
V. Pelassa
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
J. Rousselle
C. Rulten
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
binaries: general
eng
uncontrolled
gamma-rays: general
eng
uncontrolled
stars: individual (LS I+61 degrees 303, VER J0240+612)
eng
uncontrolled
X-rays: binaries
Institut für Physik und Astronomie
Referiert
Import
45604
2016
2016
eng
6
818
article
IOP Publ. Ltd.
Bristol
1
--
--
--
A SEARCH FOR BRIEF OPTICAL FLASHES ASSOCIATED WITH THE SETI TARGET KIC 8462852
The F-type star KIC. 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used to analyze nine hours of serendipitous archival observations of KIC. 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately 1 photon m(-2), is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.3847/2041-8205/818/2/L33
2041-8205
2041-8213
wos2016:2019
L33
WOS:000370444800012
Dickinson, HJ (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA.; Holder, J (reprint author), Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA.; Holder, J (reprint author), Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA.; Holder, J (reprint author), Florida Inst Technol, Dept Phys & Space Sci, W Melbourne, FL 32901 USA., hughd@iastate.edu; jholder@physics.udel.edu
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada
importub
2020-03-22T19:55:01+00:00
filename=package.tar
c286dd75d0f30aecbb7b257750b890ab
A. U. Abeysekara
S. Archambault
A. Archer
W. Benbow
R. Bird
M. Buchovecky
J. H. Buckley
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
J. L. Christiansen
L. Ciupik
W. Cui
H. J. Dickinson
J. D. Eisch
M. Errando
A. Falcone
D. J. Fegan
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
M. Huetten
Nils Hakansson
D. Hanna
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
T. T. Y. Lin
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
A. Petrashyk
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
G. Ratliff
P. T. Reynolds
G. T. Richards
E. Roache
M. Santander
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
D. A. Williams
B. Zitzer
eng
uncontrolled
astrobiology
eng
uncontrolled
extraterrestrial intelligence
eng
uncontrolled
methods: observational
eng
uncontrolled
stars: individual ( KIC 8462852)
eng
uncontrolled
techniques: photometric
Institut für Physik und Astronomie
Referiert
Import
55324
2017
2017
eng
6
2
836
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration;Fermi-LAT Collaboration
1
2017-02-21
2017-02-21
--
A Luminous and Isolated Gamma-Ray Flare from the Blazar B2 1215+30
B2 1215+30 is a BL-Lac-type blazar that was first detected at TeV energies by the MAGIC atmospheric Cherenkov telescopes and subsequently confirmed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory with data collected between 2009 and 2012. In 2014 February 08, VERITAS detected a large-amplitude flare from B2. 1215+30 during routine monitoring observations of the blazar 1ES. 1218+304, located in the same field of view. The TeV flux reached 2.4 times the Crab Nebula flux with a variability timescale of <3.6 hr. Multiwavelength observations with Fermi-LAT, Swift, and the Tuorla Observatory revealed a correlated high GeV flux state and no significant optical counterpart to the flare, with a spectral energy distribution where the gamma-ray luminosity exceeds the synchrotron luminosity. When interpreted in the framework of a onezone leptonic model, the observed emission implies a high degree of beaming, with Doppler factor delta > 10, and an electron population with spectral index p < 2.3.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/1538-4357/836/2/205
0004-637X
1538-4357
wos:2017
205
WOS:000395797900021
Errando, M (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA.; Errando, M (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., errando@physics.wustl.edu; muk@astro.columbia.edu; sfegan@llr.in2p3.fr; zefi@llr.in2p3.fr
2022-06-24T10:57:31+00:00
sword
importub
filename=package.tar
df2bdf4d093dcb4a0dbecead9175c1c3
false
true
A. U. Abeysekara
S. Archambault
A. Archer
Wystan Benbow
Ralph Bird
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
X. Chen
L. Ciupik
W. Cui
H. J. Dickinson
J. D. Eisch
M. Errando
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
M. Hutten
N. Hakansson
D. Hanna
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
T. Nguyen
D. Nieto
R. A. Ong
A. N. Otte
N. Park
V. Pelassa
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
M. Santander
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. P. Wakely
O. M. Weiner
A. Weinstein
Alina Wilhelm
D. A. Williams
S. Fegan
B. Giebels
D. Horan
A. Berdyugin
J. Kuan
E. Lindfors
K. Nilsson
A. Oksanen
H. Prokoph
R. Reinthal
L. Takalo
F. Zefi
eng
uncontrolled
BL Lacertae objects: individual (B2 1215+30, VER J1217+301)
eng
uncontrolled
galaxies: active
eng
uncontrolled
galaxies: jets
eng
uncontrolled
galaxies: nuclei
eng
uncontrolled
gamma rays: galaxies
Physik
Institut für Physik und Astronomie
Referiert
Import
37289
2014
2014
eng
11
2
797
article
IOP Publ. Ltd.
Bristol
Veritas Collaboration
1
--
--
--
Investigating broadband variability of the TeV blazar 1ES 1959+650
We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected emission model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/797/2/89
0004-637X
1538-4357
wos:2014
89
WOS:000346291600017
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., amy.furniss@gmail.com; Markus.Bottcher@nwu.ac.za
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K
E. Aliu
S. Archambault
T. Arlen
T. Aune
Anna Barnacka
M. Beilicke
W. Benbow
K. Berger
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
M. Cerruti
X. Chen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
J. Dumm
J. D. Eisch
A. Falcone
S. Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
N. Hakansson
D. Hanna
J. Holder
G. Hughes
Z. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
P. Majumdar
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
T. Nelson
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
M. Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
A. Sadun
M. Santander
G. H. Sembroski
K. Shahinyan
F. Sheidaei
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
Markus Boettcher
M. Fumagalli
eng
uncontrolled
BL Lacertae objects: individual (1ES 1959+650)
eng
uncontrolled
gamma rays: galaxies
Institut für Physik und Astronomie
Referiert
44746
2016
2016
eng
7
831
article
IOP Publ. Ltd.
Bristol
1
--
--
--
A SEARCH FOR VERY HIGH ENERGY GAMMA RAYS FROM THE MISSING LINK BINARY PULSAR J1023+0038 WITH VERITAS
The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259-63/LS 2883, making it an ideal candidate for the study of high-energy nonthermal emission. It has been the subject of multiwavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high energy (VHE) gamma-ray observations carried out by the Very Energetic Radiation Imaging Telescope Array System before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that VHE gamma rays are produced via an inverse Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than similar to 2 G before the disappearance of the radio pulsar and greater than similar to 10 G afterward.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/0004-637X/831/2/193
0004-637X
1538-4357
wos2016:2019
193
WOS:000388227500004
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., ester.aliu.fuste@gmail.com; gtrichards@gatech.edu; masha.chernyakova@dcu.ie; malloryr@gmail.com
U.S. Department of Energy Office of Science; Smithsonian Institution; NSERC in Canada; Spanish Ministerio de Economia y Competitividad (MINECO) [AYA2013-47447-C3-1-P]; U.S. National Science Foundation
importub
2020-03-22T12:45:01+00:00
filename=package.tar
d63cd1943bb5be74d6c2011b7a43eaa9
E. Aliu
S. Archambault
A. Archer
W. Benbow
R. Bird
Jonathan Biteau
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
H. J. Dickinson
J. D. Eisch
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
A. Flinders
P. Fortin
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
M. Huetten
Nils Hakansson
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
M. J. Lang
A. Loo
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
T. Nguyen
D. Nieto
R. A. Ong
A. N. Otte
D. Pandel
N. Park
V. Pelassa
A. Petrashyk
M. Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
Alina Wilhelm
D. A. Williams
B. Zitzer
M. Chernyakova
M. S. E. Roberts
eng
uncontrolled
binaries: general
eng
uncontrolled
gamma rays: general
eng
uncontrolled
pulsars: general
eng
uncontrolled
pulsars: individual (PSR J1023+0038)
Institut für Physik und Astronomie
Referiert
Import
39164
2015
2015
eng
7
1
800
article
IOP Publ. Ltd.
Bristol
1
--
--
--
A search for pulsations from geminga above 100 GeV with veritas
We present the results of 71.6 hr of observations of the Geminga pulsar (PSR J0633+1746) with the VERITAS very-high-energy gamma-ray telescope array. Data taken with VERITAS between 2007 November and 2013 February were phase-folded using a Geminga pulsar timing solution derived from data recorded by the XMM-Newton and Fermi-LAT space telescopes. No significant pulsed emission above 100 GeV is observed, and we report upper limits at the 95% confidence level on the integral flux above 135 GeV (spectral analysis threshold) of 4.0x10(-13) s(-1) cm(-2) and 1.7 x 10(-13) s(-1) cm(-2) for the two principal peaks in the emission profile. These upper limits, placed in context with phase-resolved spectral energy distributions determined from 5 yr of data from the Fermi-Large Area Telescope (LAT), constrain possible hardening of the Geminga pulsar emission spectra above similar to 50 GeV.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/800/1/61
0004-637X
1538-4357
wos:2015
61
WOS:000349236900061
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., mccann@kicp.uchicago.edu; gtrichards@gatech.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; Kavli Institute for
Cosmological Physics at the University of Chicago [NSF PHY-1125897]
E. Aliu
S. Archambault
A. Archer
T. Aune
Anna Barnacka
M. Beilicke
W. Benbow
R. Bird
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
M. Errando
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
N. H. A. Kansson
D. Hanna
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
D. Kieda
F. Krennrich
S. Kumar
M. J. Lang
M. Lyutikov
A. S. Madhavan
G. Maier
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
Manuela Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
A. Weinstein
D. A. Williams
A. Zajczyk
B. Zitzer
eng
uncontrolled
gamma rays: stars
eng
uncontrolled
pulsars: general
eng
uncontrolled
pulsars: individual (PSR J0633+1746, Geminga)
Institut für Physik und Astronomie
Referiert
45283
2016
2016
eng
19
151
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
--
--
--
UPPER LIMITS FROM FIVE YEARS OF BLAZAR OBSERVATIONS WITH THE VERITAS CHERENKOV TELESCOPES
Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) gamma-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of similar to 570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4s excess.
The astronomical journal
10.3847/0004-6256/151/6/142
0004-6256
1538-3881
wos2016:2019
142
WOS:000377990300009
Benbow, W (reprint author), Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA., wystan.benbow@cfa.harvard.edu; matteo.cerruti@lpnhe.in2p3.fr; caajohns@ucsc.edu
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada; Science and Technology Facilities Council [ST/L00075X/1]
importub
2020-03-22T17:15:01+00:00
filename=package.tar
33e112e5f9e5ea910d59c04eb1e45e3e
S. Archambault
A. Archer
W. Benbow
R. Bird
Jonathan Biteau
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
J. D. Eisch
M. Errando
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
M. Huetten
Nils Hakansson
D. Hanna
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
T. Nguyen
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
D. A. Williams
B. Zitzer
M. Fumagalli
J. X. Prochaska
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: galaxies
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert
Import
45422
2016
2016
eng
162
167
8
821
article
IOP Publ. Ltd.
Bristol
1
--
--
--
TEV GAMMA-RAY OBSERVATIONS OF THE GALACTIC CENTER RIDGE BY VERITAS
The Galactic Center ridge has been observed extensively in the past by both GeV and TeV gamma-ray instruments revealing a wealth of structure, including a diffuse component and the point sources G0.9+0.1 (a composite supernova remnant) and Sgr A* (believed to be associated with the supermassive black hole located at the center of our Galaxy). Previous very high energy (VHE) gamma-ray observations with the H.E.S.S.. experiment have also detected an extended TeV gamma-ray component along the Galactic plane in the >300 GeV gamma-ray regime. Here we report on observations of the Galactic Center ridge from 2010 to 2014 by the VERITAS telescope array in the >2 TeV energy range. From these observations we (1) provide improved measurements of the differential energy spectrum for Sgr A* in the >2 TeV gamma-ray regime, (2) provide a detection in the >2 TeV gamma-ray emission from the composite SNR G0.9+0.1 and an improved determination of its multi-TeV gamma-ray energy spectrum, and. (3) report on the detection of VER J1746-289, a localized enhancement of >2 TeV gamma-ray emission along the Galactic plane.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/0004-637X/821/2/129
0004-637X
1538-4357
wos2016:2019
129
WOS:000377102700058
Smith, AW (reprint author), Univ Maryland, College Pk, MD 20742 USA.; Smith, AW (reprint author), NASA, Goddard Space Flight Ctr, College Pk, MD 20742 USA., asmith44@umd.edu
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada; Cycle 7 Fermi Guest Investigator program [NNH13ZDA001N]
importub
2020-03-22T18:24:01+00:00
filename=package.tar
a66fdf268f7d887e2a6a53092afff963
A. Archer
W. Benbow
R. Bird
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
J. D. Eisch
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
A. Flinders
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
Nils Hakansson
D. Hanna
J. Holder
T. B. Humensky
M. Huetten
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
N. Park
V. Pelassa
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
G. Ratliff
P. T. Reynolds
G. T. Richards
E. Roache
J. Rousselle
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
V. V. Vassiliev
S. P. Wakely
O. M. Weiner
A. Weinstein
Alina Wilhelm
D. A. Williams
B. Zitzer
F. Yusef-Zadeh
eng
uncontrolled
Galaxy: center
eng
uncontrolled
gamma rays: general
eng
uncontrolled
supernovae: individual (G0.9+0.1)
Institut für Physik und Astronomie
Referiert
Import
45008
2016
2016
eng
202
208
7
461
article
Oxford Univ. Press
Oxford
1
--
--
--
Discovery of very high energy gamma rays from 1ES 1440+122
Monthly notices of the Royal Astronomical Society
10.1093/mnras/stw1319
0035-8711
1365-2966
wos2016:2019
WOS:000383272500017
Dumm, J (reprint author), Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA., dumm@physics.umn.edu
US Department of Energy Office of Science; US National Science Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the UK; South African Department of Science and Technology through the National Research Foundation under NRF SARChI Chair [64789]
importub
2020-03-22T14:56:01+00:00
filename=package.tar
b9f4dce585992c16c79f19e0e61580f4
S. Archambault
A. Archer
Anna Barnacka
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
Markus Böttcher
J. H. Buckley
V. Bugaev
J. V. Cardenzana
M. Cerruti
Xuhui Chen
J. L. Christiansen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
G. H. Gillanders
S. Godambe
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
Nils Hakansson
D. Hanna
J. Holder
G. Hughes
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
S. Kumar
M. J. Lang
A. S. Madhavan
G. Maier
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
T. Nelson
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
K. Sweeney
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. P. Wakely
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
gamma-rays: general
Institut für Physik und Astronomie
Referiert
Import
34510
2013
2013
eng
10
2
779
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration, Smithsonian Astrophys Observ
1
--
--
--
Veritas observatons of the microquasar cygnus X-3
We report results from TeV gamma-ray observations of the microquasar Cygnus X-3. The observations were made with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) over a time period from 2007 June 11 to 2011 November 28. VERITAS is most sensitive to gamma rays at energies between 85 GeV and 30 TeV. The effective exposure time amounts to a total of about 44 hr, with the observations covering six distinct radio/X-ray states of the object. No significant TeV gamma-ray emission was detected in any of the states, nor with all observations combined. The lack of a positive signal, especially in the states where GeV gamma rays were detected, places constraints on TeV gamma-ray production in Cygnus X-3. We discuss the implications of the results.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/779/2/150
0004-637X
1538-4357
wos:2011-2013
WOS:000328187200059
Cui, W (reprint author), Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA., cui@purdue.edu; avarlott@purdue.edu
NASA through a Fermi GI grant [NNX11AP90G]; Purdue University; U.S.
Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.
S. Archambault
M. Beilicke
W. Benbow
K. Berger
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
C. Duke
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
M. J. Lang
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
D. Nieto
A. O'Faolain de Bhroithe
R. A. Ong
A. N. Otte
D. Pandel
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
F. Sheidaei
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. V. Tucci
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
D. A. Williams
B. Zitzer
M. L. McCollough
eng
uncontrolled
acceleration of particles
eng
uncontrolled
binaries: close
eng
uncontrolled
gamma rays: stars
eng
uncontrolled
X-rays: individual (Cygnus X-3)
Institut für Physik und Astronomie
Referiert
37431
2014
2014
eng
6
1
795
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Constraints on very high energy emission from GRB 130427A
Prompt emission from the very fluent and nearby (z = 0.34) gamma-ray burst GRB130427A was detected by several orbiting telescopes and by ground-based, wide-field-of-view optical transient monitors. Apart from the intensity and proximity of this GRB, it is exceptional due to the extremely long-lived high-energy (100 MeV to 100 GeV) gamma-ray emission, which was detected by the Large Area Telescope on the Fermi Gamma-Ray Space Telescope for similar to 70 ks after the initial burst. The persistent, hard-spectrum, high-energy emission suggests that the highest-energy gamma rays may have been produced via synchrotron self-Compton processes though there is also evidence that the high-energy emission may instead be an extension of the synchrotron spectrum. VERITAS, a ground-based imaging atmospheric Cherenkov telescope array, began follow-up observations of GRB130427A similar to 71 ks (similar to 20 hr) after the onset of the burst. The GRB was not detected with VERITAS; however, the high elevation of the observations, coupled with the low redshift of the GRB, make VERITAS a very sensitive probe of the emission from GRB130427A for E > 100 GeV. The non-detection and consequent upper limit derived place constraints on the synchrotron self-Compton model of high-energy gamma-ray emission from this burst.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.1088/2041-8205/795/1/L3
2041-8205
2041-8213
wos:2014
L3
WOS:000345455500003
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., aune@astro.ucla.edu; veres@email.gwu.edu; sjzhu@umd.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K; NASA [NNX12AE30G]
E. Aliu
T. Aune
Anna Barnacka
M. Beilicke
W. Benbow
K. Berger
Jonathan Biteau
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
V. Connaughton
W. Cui
H. J. Dickinson
J. D. Eisch
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
Nils Hakansson
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
A. S. Madhavan
G. Maier
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
Martin Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
O. M. Weiner
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
B. Zitzer
J. E. McEnery
J. S. Perkins
P. Veres
S. Zhu
eng
uncontrolled
gamma-ray burst: individual (GRB 130427A)
Institut für Physik und Astronomie
Referiert
37821
2014
2014
eng
7
2
787
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Investigating the TeV morpholoy of MGRO J1908+06 with veritas
We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14 sigma) and measure a photon index of 2.20 +/- 0.10(stat) +/- 0.20(sys). The TeV emission is extended, covering the region near PSR J1907+0602 and also extending toward SNR G40.5-0.5. When fitted with a two-dimensional Gaussian, the intrinsic extension has a standard deviation of sigma(src) = 0 degrees.44 +/- 0 degrees.02. In contrast to other TeV PWNe of similar age in which the TeV spectrum softens with distance from the pulsar, the TeV spectrum measured near the pulsar location is consistent with that measured at a position near the rim of G40.5-0.5, 0 degrees.33 away.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/787/2/166
0004-637X
1538-4357
wos:2014
166
WOS:000336246700071
Aliu, E (reprint author), Columbia Univ, Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA.
U.S. Department of Energy Office of Science; U.S. National Science
Foundation and the Smithsonian Institution; NSERC in Canada; Science
Foundation Ireland [SFI 10/RFP/AST2748]; STFC in the U.K
E. Aliu
S. Archambault
T. Aune
B. Behera
M. Beilicke
W. Benbow
K. Berger
R. Bird
J. H. Buckley
V. Bugaev
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
J. Dumm
Vikram V. Dwarkadas
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
F. Krennrich
S. Kumar
M. J. Lang
A. S. Madhavan
G. Maier
A. J. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
D. Pandel
N. Park
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
G. Ratliff
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
J. Rousselle
G. H. Sembroski
K. Shahinyan
F. Sheidaei
A. W. Smith
D. Staszak
Igor O. Telezhinsky
K. Tsurusaki
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. Vincent
S. P. Wakely
J. E. Ward
A. Weinstein
R. Welsing
Alina Wilhelm
eng
uncontrolled
gamma rays: general
eng
uncontrolled
gamma-ray burst: individual (MGRO J1908+06, VER J1907+062)
eng
uncontrolled
pulsars: individual (PSR J1907+0602)
eng
uncontrolled
ISM: supernova remnants
Institut für Physik und Astronomie
Referiert
36605
2011
2011
eng
5
2
738
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Veritas observations of unusual extragalactic transient swift J164449.3+573451
We report on very high energy (>100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the Swift Observatory and later detected by multiple radio, optical, and X-ray observatories. A total exposure of 28 hr was obtained on Swift J164449.3+573451 with the Very Energetic Radiation Imaging Telescope Array System ( VERITAS) during 2011 March 28-April 15. We do not detect the source and place a differential upper limit on the emission at 500 GeV during these observations of 1.4 x 10(-12) erg cm(-2) s(-1) (99% confidence level). We also present time-resolved upper limits and use a flux limit averaged over the X-ray flaring period to constrain various emission scenarios that can accommodate both the radio-through-X-ray emission detected from the source and the lack of detection by VERITAS.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.1088/2041-8205/738/2/L30
2041-8205
wos:2011-2013
L30
WOS:000294760700014
Aliu, E (reprint author), Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA., apbouvie@ucsc.edu; boettchm@ohio.edu; daniel-d-gall@uiowa.edu
U.S. Department of Energy; U.S. National Science Foundation; Smithsonian
Institution; NSERC in Canada; Science Foundation Ireland (SFI)
[10/RFP/AST2748]; STFC in the UK
E. Aliu
T. Arlen
T. Aune
M. Beilicke
W. Benbow
Markus Boettcher
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
A. Cannon
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
R. Dickherber
M. Errando
A. Falcone
J. P. Finley
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
S. Griffin
J. Grube
G. Gyuk
D. Hanna
J. Holder
H. Huan
G. Hughes
C. M. Hui
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
H. Krawczynski
F. Krennrich
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
R. A. Ong
M. Orr
A. N. Otte
N. Park
J. S. Perkins
A. Pichel
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
J. Ruppel
D. B. Saxon
M. Schroedter
G. H. Sembroski
C. Skole
A. W. Smith
D. Staszak
G. Tesic
M. Theiling
S. Thibadeau
K. Tsurusaki
J. Tyler
A. Varlotta
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
A. Weinstein
T. Weisgarber
D. A. Williams
eng
uncontrolled
accretion, accretion disks
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: galaxies
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert
34523
2013
2013
eng
7
1
779
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Multiwavelemght oservatons of the TeV binary LS I+61 degrees 303 with veritas, fermi-lat, and swift/XRT during a TeV outburst
We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61 degrees 303 with the VERITAS telescope array (>200 GeV), Fermi-LAT (0.3-300 GeV), and Swift/XRT (2-10 keV). The data were taken from 2011 December through 2012 January and show a strong detection in all three wavebands. During this period VERITAS obtained 24.9 hr of quality selected livetime data in which LS I +61 degrees 303 was detected at a statistical significance of 11.9 sigma. These TeV observations show evidence for nightly variability in the TeV regime at a post-trial significance of 3.6 sigma. The combination of the simultaneously obtained TeV and X-ray fluxes do not demonstrate any evidence for a correlation between emission in the two bands. For the first time since the launch of the Fermi satellite in 2008, this TeV detection allows the construction of a detailed MeV-TeV spectral energy distribution from LS I +61 degrees 303. This spectrum shows a distinct cutoff in emission near 4 GeV, with emission seen by the VERITAS observations following a simple power-law above 200 GeV. This feature in the spectrum of LS I +61 degrees 303, obtained from overlapping observations with Fermi-LAT and VERITAS, may indicate that there are two distinct populations of accelerated particles producing the GeV and TeV emission.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/779/1/88
0004-637X
1538-4357
wos:2011-2013
WOS:000328160100088
Aliu, E (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA., sheidaei@physics.utah.edu; aw.smith@utah.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.
E. Aliu
S. Archambault
B. Behera
K. Berger
M. Beilicke
W. Benbow
R. Bird
A. Bouvier
V. Bugaev
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
J. Dumm
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
F. Krennrich
M. J. Lang
G. Maier
P. Majumdar
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
A. O'Faolain de Bhroithe
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
Martin Pohl
A. Popkow
H. Prokoph
J. Quinn
K. Ragan
J. Rajotte
G. Ratliff
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
F. Sheidaei
C. Skole
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
A. Zajczyk
B. Zitzer
eng
uncontrolled
acceleration of particles
eng
uncontrolled
binaries: general
eng
uncontrolled
gamma rays: stars
eng
uncontrolled
relativistic processes
eng
uncontrolled
X-rays: binaries
Institut für Physik und Astronomie
Referiert
55140
2017
2017
eng
14
8
95
article
American Physical Society
College Park
VERITAS Collaboration
1
2017-04-05
2017-04-05
--
Dark matter constraints from a joint analysis of dwarf Spheroidal galaxy observations with VERITAS
We present constraints on the annihilation cross section of weakly interacting massive particles dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of similar to 230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35 x 10(-23) cm(3) s(-1) at 1 TeV for the bottom quark (b (b) over bar) final state, 2.85 x 10(-24) cm(3) s(-1) at 1 TeV for the tau lepton (tau+tau(-)) final state and 1.32 x 10-25 cm(3) s(-1) at 1 TeV for the gauge boson (gamma gamma) final state.
Physical review : D, Particles, fields, gravitation, and cosmology
10.1103/PhysRevD.95.082001
2470-0010
2470-0029
wos:2017
082001
WOS:000406742300001
Zitzer, B (reprint author), McGill Univ, Phys Dept, Montreal, PQ H3A 2T8, Canada.; Geringer-Sameth, A; Koushiappas, S (reprint author), Brown Univ, Dept Phys, Providence, RI 02912 USA.; Geringer-Sameth, A (reprint author), Carnegie Mellon Univ, Dept Phys, McWilliams Ctr Cosmol, Pittsburgh, PA 15213 USA.; Koushiappas, S (reprint author), Harvard Univ, Inst Theory & Computat, 60 Garden St, Cambridge, MA 02138 USA., a.geringer-sameth@imperial.ac.uk; koushiappas@brown.edu; bzitzer@physics.mcgill.ca
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; Natural Sciences and Engineering Research Council of Canada (NSERC) in Canada; Department of Energy [DE-SC0010010]; Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231]
2022-06-10T10:35:24+00:00
sword
importub
filename=package.tar
34dae3477ba0618d47e3c55c3f4e5bc6
S. Archambault
A. Archer
W. Benbow
R. Bird
E. Bourbeau
T. Brantseg
M. Buchovecky
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
J. L. Christiansen
M. P. Connolly
W. Cui
M. K. Daniel
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
A. Geringer-Sameth
S. Griffin
J. Grube
M. Hütten
N. Hakansson
D. Hanna
O. Hervet
J. Holder
G. Hughes
B. Hummensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
S. Koushiappas
M. Krause
F. Krennrich
M. J. Lang
T. T. Y. Lin
S. McArthur
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
M. Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
I. Sadeh
M. Santander
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
S. Trepanier
J. V. Tucci
J. Tyler
S. P. Wakely
A. Weinstein
P. Wilcox
D. A. Williams
B. Zitzer
Physik
Institut für Physik und Astronomie
Referiert
Import
39243
2015
2015
eng
2456
2467
12
3
446
article
Oxford Univ. Press
Oxford
VERITAS Collaboration
1
--
--
--
The most powerful flaring activity from the NLSyl PMN J0948+0022
We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in gamma-rays, PMN J0948+0022 (z = 0.5846). A y -ray flare was observed by the Large Area Telescope on board Fermi during 2012 December-2013 January, reaching a daily peak flux in the 0.1-100 GeV energy range of (155 31) x 10 8 ph cm(-2) S-1 on 2013 January 1, corresponding to an apparent isotropic luminosity of similar to 1.5 x 1048 erg s(-1). The y -ray flaring period triggered Swift and Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations in addition to radio and optical monitoring by Owens Valley Radio Observatory, Monitoring Of Jets in Active galactic nuclei with VLBA Experiments, and Catalina Real-time Transient Survey. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the y -ray flare, reaching a record flux for this source from optical to y gamma-rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6-17 resulted in an upper limit of F>0.2 Trev < 4.0 x 10(-12) ph cm(-2) s(-1). We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. The two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.
Monthly notices of the Royal Astronomical Society
10.1093/mnras/stu2251
0035-8711
1365-2966
wos:2015
WOS:000350272300020
dammando@ira.inaf.it; dammando@ira.inaf.it; dammando@ira.inaf.it; dammando@ira.inaf.it; dammando@ira.inaf.it; dammando@ira.inaf.it; dammando@ira.inaf.it
US Department of Energy Office of Science; Smithsonian Institution; NSERC in Canada; Science Foundation Ireland [SFI 10/RFP/AST2748]; Science and Technology Facilities Council in the UK; NASA [NNX08AW31G, NNX11A043G]; NSF [AST-0808050, AST-1109911]; US National Science Foundation [AST-0909182]; Fermi Guest Investigator grants [NNX08AW56G, NNX09AU10G, NNX12AO93G]
M. Orienti
J. Finke
C. M. Raiteri
T. Hovatta
J. Larsson
W. Max-Moerbeck
J. Perkins
A. C. S. Readhead
J. L. Richards
M. Beilicke
W. Benbow
K. Berger
R. Bird
V. Bugaev
J. V. Cardenzana
M. Cerruti
Xuhui Chen
L. Ciupik
H. J. Dickinson
J. D. Eisch
M. Errando
A. Falcone
J. P. Finley
H. Fleischhack
P. Fortin
L. Fortson
A. Furniss
L. Gerard
G. H. Gillanders
S. T. Griffiths
J. Grube
G. Gyuk
Nils Hakansson
J. Holder
T. B. Humensky
P. Kar
M. Kertzman
Y. Khassen
D. Kieda
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
Manuela Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
J. Rousselle
M. Santander
G. H. Sembroski
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
V. V. Vassiliev
S. P. Wakely
A. Weinstein
R. Welsing
D. A. Williams
B. Zitzer
eng
uncontrolled
galaxies: active-galaxies: individual: PMN J0948+0022
eng
uncontrolled
galaxies: nuclei
eng
uncontrolled
galaxies: Seyfert
eng
uncontrolled
gamma-rays: general
Institut für Physik und Astronomie
Referiert
46216
2017
2017
eng
1188
1204
6
233
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Discovery of Very-high-energy Emission from RGB J2243+203 and Derivation of Its Redshift Upper Limit
Very-high-energy (VHE; > 100 GeV) gamma-ray emission from the blazar RGB J2243+203 was discovered with the VERITAS Cherenkov telescope array, during the period between 2014 December 21 and 24. The VERITAS energy spectrum from this source can be fitted by a power law with a photon index of 4.6 +/- 0.5, and a flux normalization at 0.15 TeV of (6.3 +/- 1.1) x 10(-10) cm(-2) s(-1) TeV-1. The integrated Fermi-LAT flux from 1 to 100 GeV during the VERITAS detection is (4.1 +/- 0.8) x 10(-8) cm(-2) s(-1), which is an order of magnitude larger than the four-year-averaged flux in the same energy range reported in the 3FGL catalog, (4.0 +/- 0.1 x 10(-9) cm(-2) s(-1)). The detection with VERITAS triggered observations in the X-ray band with the Swift-XRT. However, due to scheduling constraints Swift-XRT observations were performed 67 hr after the VERITAS detection, rather than simultaneously with the VERITAS observations. The observed X-ray energy spectrum between 2 and 10 keV can be fitted with a power law with a spectral index of 2.7 +/- 0.2, and the integrated photon flux in the same energy band is (3.6 +/- 0.6) x 10(-13) cm(-2) s(-1). EBL-model-dependent upper limits of the blazar redshift have been derived. Depending on the EBL model used, the upper limit varies in the range from z < 0.9 to z < 1.1.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series
10.3847/1538-4365/aa8d76
0067-0049
1538-4365
wos:2017
7
WOS:000415043000006
Abeysekara, AU (reprint author), Univ Utah, Dept Phys & Astron, Salt Lake City, UT 84112 USA.
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada
importub
2020-04-19T23:37:01+00:00
filename=package.tar
08a516b0e7710f283e9c39dc94ad4f75
A. U. Abeysekara
S. Archambault
A. Archer
W. Benbow
R. Bird
Robert Brose
M. Buchovecky
J. H. Buckley
V. Bugaev
M. Cerruti
M. P. Connolly
W. Cui
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
M. Huetten
D. Hanna
O. Hervet
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
A. Petrashyk
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
I. Sadeh
M. Santander
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. Tyler
V. V. Vassiliev
S. P. Wakely
O. M. Weiner
A. Weinstein
P. Wilcox
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
galaxies: individual (RGB J2243+203)
Institut für Physik und Astronomie
Referiert
Import
55040
2017
2017
eng
34
43
10
91
article
Elsevier
Amsterdam
1
2017-03-02
2017-03-02
--
Gamma-ray observations under bright moonlight with VERITAS
Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so IACTs cannot be operated in the same configuration in the presence of bright moonlight as under dark skies. Since September 2012, observations have been carried out with the VERITAS IACTs under bright moonlight (defined as about three times the night-sky-background (NSB) of a dark extragalactic field, typically occurring when Moon illumination > 35%) in two observing modes, firstly by reducing the voltage applied to the PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to the cameras. This has allowed observations at up to about 30 times previous NSB levels (around 80% Moon illumination), resulting in 30% more observing time between the two modes over the course of a year. These additional observations have already allowed for the detection of a flare from the 1ES 1727 + 502 and for an observing program targeting a measurement of the cosmic-ray positron fraction. We provide details of these new observing modes and their performance relative to the standard VERITAS observations. (C) 2017 Elsevier B.V. All rights reserved.
Astroparticle physics
10.1016/j.astropartphys.2017.03.001
0927-6505
1873-2852
wos:2017
WOS:000401213600005
Griffin, S (reprint author), McGill Univ, Phys Dept, Montreal, PQ H3A 2T8, Canada.; Bird, R (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.; Bird, R (reprint author), Univ Coll Dublin, Sch Phys, Dublin 4, Ireland., ralphbird@astro.ucla.edu; griffins@physics.mcgill.ca
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada; DGPP; European Regional Development Fund (ERDF)
2022-05-30T11:02:20+00:00
sword
importub
filename=package.tar
751b1e11a05588e828e1beaad32f6816
Griffin, S.
Bird, Ralph
false
true
S. Archambault
A. Archer
W. Benbow
Ralph Bird
E. Bourbeau
A. Bouvier
M. Buchovecky
V. Bugaev
J. V. Cardenzana
M. Cerruti
L. Ciupik
M. P. Connolly
W. Cui
M. K. Daniel
M. Errando
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
D. Hanna
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
M. Hutten
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
D. Kieda
M. Krause
M. J. Lang
T. T. Y. Lin
G. Maier
S. McArthur
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
I. Sadeh
G. H. Sembroski
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
S. Trepanier
S. P. Wakely
A. Weinstein
P. Wilcox
D. A. Williams
B. Zitzer
eng
uncontrolled
Instrumentation
eng
uncontrolled
Moonlight
eng
uncontrolled
Observing methods
eng
uncontrolled
VERITAS
eng
uncontrolled
IACT
Astronomie und zugeordnete Wissenschaften
Physik
Institut für Physik und Astronomie
Referiert
Import
51952
2018
2018
eng
7
6
98
article
American Physical Society
College Park
VERITAS Collaboration
1
2018-09-20
--
--
Measurement of cosmic-ray electrons at TeV energies by VERITAS
Cosmic-ray electrons and positrons (CREs) at GeV-TeV energies are a unique probe of our local Galactic neighborhood. CREs lose energy rapidly via synchrotron radiation and inverse-Compton scattering processes while propagating within the Galaxy, and these losses limit their propagation distance. For electrons with TeV energies, the limit is on the order of a kiloparsec. Within that distance, there are only a few known astrophysical objects capable of accelerating electrons to such high energies. It is also possible that the CREs are the products of the annihilation or decay of heavy dark matter (DM) particles. VERITAS, an array of imaging air Cherenkov telescopes in southern Arizona, is primarily utilized for gamma-ray astronomy but also simultaneously collects CREs during all observations. We describe our methods of identifying CREs in VERITAS data and present an energy spectrum, extending from 300 GeV to 5 TeV, obtained from approximately 300 hours of observations. A single power-law fit is ruled out in VERITAS data. We find that the spectrum of CREs is consistent with a broken power law, with a break energy at 710 +/- 40(stat) +/- 140(syst) GeV.
Physical review : D, Particles, fields, gravitation, and cosmology
10.1103/PhysRevD.98.062004
2470-0010
2470-0029
wos:2018
062004
WOS:000445175300001
Staszak, D (reprint author), Univ Chicago, Enrico Fermi Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA., d.staszak@gmail.com; bzitzer@physics.mcgill.ca
U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; Canada Foundation for Innovation (CFI)Canada Foundation for Innovation; NanoQuebec; Fonds de recherche du Quebec-Nature et technologies (FRQ-NT)
2021-09-27T09:14:47+00:00
sword
importub
filename=package.tar
1346d8d2817f7be22cb9103671955744
false
true
A. Archer
W. Benbow
R. Bird
Robert Brose
M. Buchovecky
J. H. Buckley
V. Bugaev
M. P. Connolly
W. Cui
M. K. Daniel
Q. Feng
J. P. Finley
L. Fortson
A. Furniss
G. Gillanders
M. Huetten
D. Hanna
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
T. T. Y. Lin
G. Maier
S. McArthur
P. Moriarty
R. Mukherjee
R. A. Ong
A. N. Otte
A. Petrashyk
M. Pohl
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
I. Sadeh
M. Santander
G. H. Sembroski
D. Staszak
I. Sushch
S. P. Wakely
R. M. Wells
P. Wilcox
Alina Wilhelm
D. A. Williams
T. J. Williamson
B. Zitzer
Physik
Institut für Physik und Astronomie
Referiert
Import
Bronze Open-Access
55355
2017
2017
eng
12
2
835
article
IOP Publ. Ltd.
Bristol
1
2017-02-02
2017-02-02
--
Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGNs), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma-rays from an AGN interact with extragalactic background light (EBL) photons to produce electron-positron pairs, which then interact with cosmic microwave background photons via inverse-Compton scattering to produce gamma-rays. Due to the deflection of the electron- positron pairs, a non-zero intergalactic magnetic field (IGMF) would potentially produce detectable effects on the angular distribution of the cascade emission. In particular, an angular broadening compared to the unscattered emission could occur. Through non-detection of angularly broadened emission from 1ES 1218 vertical bar 304, the source with the largest predicted cascade fraction, we exclude a range of IGMF strengths around 10(-14) G at the 95% confidence level. The extent of the exclusion range varies with the assumptions made about the intrinsic spectrum of 1ES. 1218+304 and the EBL model used in the simulation of the cascade process. All of the sources are used to set limits on the flux due to extended emission.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/1538-4357/835/2/288
0004-637X
1538-4357
wos:2017
288
WOS:000401226000002
Archambault, S (reprint author), McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada.
2022-06-27T12:34:45+00:00
sword
importub
filename=package.tar
62a8a6c1293a5c47df1c0553b8262527
false
true
S. Archambault
A. Archer
W. Benbow
M. Buchovecky
V. Bugaev
M. Cerruti
M. P. Connolly
W. Cui
A. Falcone
M. Fernandez Alonso
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
S. Griffin
M. Hutten
O. Hervet
J. Holder
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
D. Kieda
M. Krause
F. Krennrich
M. J. Lang
T. T. Y. Lin
G. Maier
S. McArthur
P. Moriarty
D. Nieto
R. A. Ong
A. N. Otte
M. Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
I. Sadeh
K. Shahinyan
D. Staszak
Igor O. Telezhinsky
J. Tyler
S. P. Wakely
A. Weinstein
T. Weisgarber
P. Wilcox
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: galaxies
eng
uncontrolled
magnetic fields
Physik
Institut für Physik und Astronomie
Referiert
Import
38148
2014
2014
eng
7
1
781
article
IOP Publ. Ltd.
Bristol
1
--
--
--
A search for enhanced very high energy GAMMA-RAY emission from the 2013 march crab nebula flare
In 2013 March, a flaring episode from the Crab Nebula lasting similar to 2 weeks was detected by Fermi-LAT (Large Area Telescope on board the Fermi Gamma-ray Space Telescope). The Very Energetic Radiation Imaging Telescope Array System (VERITAS) provides simultaneous observations throughout this period. During the flare, Fermi-LAT detected a 20 fold increase in flux above the average synchrotron flux >100 MeV seen from the Crab Nebula. Simultaneous measurements with VERITAS are consistent with the non-variable long-term average Crab Nebula flux at TeV energies. Assuming a linear correlation between the very high energy flux change >1 TeV and the flux change seen in the Fermi-LAT band >100 MeV during the period of simultaneous observations, the linear correlation factor can be constrained to be at most 8.6 x 10(-3) with 95% confidence.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.1088/2041-8205/781/1/L11
2041-8205
2041-8213
wos:2014
L11
WOS:000329582400011
Aliu, E (reprint author), Columbia Univ, Dept Phys & Astron, Barnard Coll, New York, NY 10027 USA.
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; STFC in the U.K.
E. Aliu
S. Archambault
T. Aune
W. Benbow
K. Berger
R. Bird
A. Bouvier
J. H. Buckley
V. Bugaev
K. Byrum
M. Cerruti
Xuhui Chen
L. Ciupik
M. P. Connolly
W. Cui
J. Dumm
M. Errando
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
P. Fortin
L. Fortson
A. Furniss
N. Galante
G. H. Gillanders
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
D. Hanna
J. Holder
G. Hughes
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
F. Krennrich
S. Kumar
M. J. Lang
M. Lyutikov
G. Maier
S. McArthur
A. McCann
K. Meagher
J. Millis
P. Moriarty
R. Mukherjee
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
M. Pohl
A. Popkow
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
F. Sheidaei
A. W. Smith
D. Staszak
Igor O. Telezhinsky
M. Theiling
J. V. Tucci
J. Tyler
A. Varlotta
S. P. Wakely
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
A. Zajczyk
B. Zitzer
eng
uncontrolled
gamma rays: general
eng
uncontrolled
ISM: individual objects (Crab Nebula)
Institut für Physik und Astronomie
Referiert
52437
2018
2018
eng
15
2
98
article
American Physical Society
College Park
VERITAS Collaboration
1
2018-05-31
2018-05-31
--
Measurement of the iron spectrum in cosmic rays by VERITAS
We present a new measurement of the energy spectrum of iron nuclei in cosmic rays from 20 TeV to 500 TeV; The measurement makes use of a template-based analysis method, which, for the first time, is applied to the energy reconstruction of iron-induced air showers recorded by the VERITAS array of imaging atmospheric Cherenkov telescopes. The event selection makes use of the direct Cherenkov light which is emitted by charged particles before the first interaction, as well as other parameters related to the shape of the recorded air shower images. The measured spectrum is well described by a power law dF/dE = f(0) center dot (E/E-0)(-gamma) over the full energy range, with gamma = 2.82 +/- 0.30(stat)(-0.27)(+0.24)(syst) and f(0) = (4.82 +/- 0.98(stat)(-2.70)(+2.12)(syst)) x 10(-7) m(-2) s(-1) TeV-1 sr(-1) at E-0 = 50 TeV, with no indication of a cutoff or spectral break. The measured differential flux is compatible with previous results, with improved statistical uncertainty at the highest energies.
Physical review : D, Particles, fields, gravitation, and cosmology
10.1103/PhysRevD.98.022009
2470-0010
2470-0029
wos:2018
022009
WOS:000439734900001
Fleischhack, H (reprint author), DESY, Platanenallee 6, D-15738 Zeuthen, Germany.; Fleischhack, H (reprint author), Michigan Technol Univ, 1400 Townsend Dr, Houghton, MI 49931 USA., hfleisch@mtu.edu
U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; Helmholtz Alliance for Astroparticle Physics
2021-10-28T08:48:05+00:00
sword
importub
filename=package.tar
1d4647bf1238171f84556889488d8101
false
true
A. Archer
W. Benbow
R. Bird
Robert Brose
M. Buchovecky
V. Bugaev
M. P. Connolly
W. Cui
M. K. Daniel
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
D. Hanna
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
M. Hutten
C. A. Johnson
P. Kaaret
N. Kelley-Hoskins
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
A. Petrashyk
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
I. Sadeh
J. Tyler
S. P. Wakely
O. M. Weiner
P. Wilcox
Alina Wilhelm
D. A. Williams
S. A. Wissel
B. Zitzer
Physik
Institut für Physik und Astronomie
Referiert
Import
Bronze Open-Access
38076
2014
2014
eng
1
10
10
54
article
Elsevier
Amsterdam
1
--
--
--
Observation of Markarian 421 in TeV gamma rays over a 14-year time span
The variability of the blazar Markarian 421 in TeV gamma rays over a 14-year time period has been explored with the Whipple 10 m telescope. It is shown that the dynamic range of its flux variations is large and similar to that in X-rays. A correlation between the X-ray and TeV energy bands is observed during some bright flares and when the complete data sets are binned on long timescales. The main database consists of 878.4 h of observation with the Whipple telescope, spread over 783 nights. The peak energy response of the telescope was 400 GeV with 20% uncertainty. This is the largest database of any TeV-emitting active galactic nucleus (AGN) and hence was used to explore the variability profile of Markarian 421. The tithe-averaged flux from Markarian 421 over this period was 0.446 +/- 0.008 Crab flux units. The flux exceeded 10 Crab flux units on three separate occasions. For the 2000-2001 season the average flux reached 1.86 Crab units, while in the 1996-1997 season the average flux was only 0.23 Crab units.
Astroparticle physics
10.1016/j.astropartphys.2013.10.004
0927-6505
1873-2852
wos:2014
WOS:000332434700001
Weekes, TC (reprint author), Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA., pat.moriarty@gmit.ie; weekes@veritas.sao.arizona.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the U.K.
V. A. Acciari
T. Arlen
T. Aune
W. Benbow
R. Bird
A. Bouvier
S. M. Bradbury
J. H. Buckley
V. Bugaev
I. de la Calle Perez
D. A. Carter-Lewis
A. Cesarini
L. Ciupik
E. Collins-Hughes
M. P. Connolly
W. Cui
C. Duke
J. Dumm
A. Falcone
Simone Federici
D. J. Fegan
S. J. Fegan
J. P. Finley
G. Finnegan
L. Fortson
J. Gaidos
N. Galante
D. Gall
K. Gibbs
G. H. Gillanders
S. Griffin
J. Grube
G. Gyuk
D. Hanna
D. Horan
T. B. Humensky
P. Kaaret
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
F. Krennrich
M. J. Lang
J. E. McEnery
A. S. Madhavan
P. Moriarty
T. Nelson
R. A. Ong
M. Orr
A. N. Otte
J. S. Perkins
D. Petry
A. Pichel
M. Pohl
J. Quinn
K. Ragan
T. Reynolds
E. Roache
A. Rovero
M. Schroedter
G. H. Sembroski
A. Smith
Igor O. Telezhinsky
M. Theiling
J. Toner
J. Tyler
A. Varlotta
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
R. Welsing
D. A. Williams
S. Wissel
eng
uncontrolled
AGN
eng
uncontrolled
TeV gamma rays
eng
uncontrolled
Markarian 421
Institut für Physik und Astronomie
Referiert
48358
2019
2019
eng
8
2
885
article
IOP Publ. Ltd.
Bristol
1
2019-11-10
2019-11-11
--
Measurement of the Extragalactic Background Light Spectral Energy Distribution with VERITAS
The extragalactic background light (EBL), a diffuse photon field in the optical and infrared range, is a record of radiative processes over the universe?s history. Spectral measurements of blazars at very high energies (>100 GeV) enable the reconstruction of the spectral energy distribution (SED) of the EBL, as the blazar spectra are modified by redshift- and energy-dependent interactions of the gamma-ray photons with the EBL. The spectra of 14 VERITAS-detected blazars are included in a new measurement of the EBL SED that is independent of EBL SED models. The resulting SED covers an EBL wavelength range of 0.56?56 ?m, and is in good agreement with lower limits obtained by assuming that the EBL is entirely due to radiation from cataloged galaxies.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/1538-4357/ab4817
0004-637X
1538-4357
wos:2019
150
WOS:000501793100001
Pueschel, E (reprint author), DESY, Platanenallee 6, D-15738 Zeuthen, Germany., elisa.pueschel@desy.de
U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; National Science FoundationNational Science Foundation (NSF); U.S. Energy (DOE); National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility [DE-AC02-05CH11231]; Marie Curie Intra-European Fellowship within the 7th European Community Framework ProgrammeEuropean Union (EU); Young Investigators Program of the Helmholtz Association; DJEI/DES/SFI/HEA Irish Centre for High-End Computing (ICHEC)
importub
2020-11-20T10:12:00+00:00
filename=package.tar
53b1aca83eda93dcd422c7c5ad8a6609
false
true
A. U. Abeysekara
A. Archer
Wystan Benbow
Ralph Bird
A. Brill
Robert Brose
M. Buchovecky
D. Calderon-Madera
J. L. Christiansen
W. Cui
M. K. Daniel
A. Falcone
Q. Feng
M. Fernandez-Alonso
J. P. Finley
Lucy Fortson
Amy Furniss
A. Gent
C. Giuri
O. Gueta
David Hanna
T. Hassan
Oliver Hervet
J. Holder
G. Hughes
T. B. Humensky
Caitlin A. Johnson
P. Kaaret
M. Kertzman
David Kieda
Maria Krause
F. Krennrich
S. Kumar
M. J. Lang
Gernot Maier
P. Moriarty
Reshmi Mukherjee
M. Nievas-Rosillo
R. A. Ong
Konstantin Johannes Pfrang
Martin Pohl
R. R. Prado
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
D. Ribeiro
G. T. Richards
E. Roache
A. C. Rovero
Iftach Sadeh
M. Santander
G. H. Sembroski
Karlen Shahinyan
Iurii Sushch
T. Svraka
A. Weinstein
R. M. Wells
Patrick Wilcox
Alina Wilhelm
David Arnold Williams
T. J. Williamson
B. Zitzer
eng
uncontrolled
Extragalactic astronomy
eng
uncontrolled
Active galactic nuclei
eng
uncontrolled
Diffuse radiation
eng
uncontrolled
Cosmology
Astronomie und zugeordnete Wissenschaften
Institut für Physik und Astronomie
Referiert
Open Access
Import
Green Open-Access
49433
2019
2019
eng
14
2
876
article
IOP Publ. Ltd.
Bristol
1
2019-05-08
2019-05-08
--
A Search for Pulsed Very High-energy Gamma-Rays from 13 Young Pulsars in Archival VERITAS Data
We conduct a search for periodic emission in the very high-energy (VHE) gamma-ray band (E > 100 GeV) from a total of 13 pulsars in an archival VERITAS data set with a total exposure of over 450 hr. The set of pulsars includes many of the brightest young gamma-ray pulsars visible in the Northern Hemisphere. The data analysis resulted in nondetections of pulsed VHE gamma-rays from each pulsar. Upper limits on a potential VHE gamma-ray flux are derived at the 95% confidence level above three energy thresholds using two methods. These are the first such searches for pulsed VHE emission from each of the pulsars, and the obtained limits constrain a possible flux component manifesting at VHEs as is seen for the Crab pulsar.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/1538-4357/ab14f4
0004-637X
1538-4357
wos:2019
95
WOS:000467460700006
Archer, A (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA., grichard@udel.edu; mathan.tyler@mail.mcgill.ca
U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; Canada
2021-02-11T12:31:38+00:00
sword
importub
filename=package.tar
ef8870f65d638ecf9322f6fdae2f60e9
Archer, A.
false
true
A. Archer
Wystan Benbow
Ralph Bird
Robert Brose
M. Buchovecky
J. H. Buckley
A. J. Chromey
Wei Cui
A. Falcone
Qi Feng
J. P. Finley
Lucy Fortson
Amy Furniss
A. Gent
O. Gueta
David Hanna
T. Hassan
Olivier Hervet
J. Holder
G. Hughes
T. B. Humensky
Caitlin A. Johnson
Philip Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
David Kieda
F. Krennrich
S. Kumar
M. J. Lang
T. T. Y. Lin
A. McCann
P. Moriarty
Reshmi Mukherjee
R. A. Ong
Adam Nepomuk Otte
D. Pandel
N. Park
A. Petrashyk
Martin Pohl
Elisa Pueschel
J. Quinn
K. Ragan
Gregory T. Richards
E. Roache
I Sadeh
Marcos Santander
S. S. Scott
G. H. Sembroski
Karlen Shahinyan
Iurii Sushch
J. Tyler
S. P. Wakely
A. Weinstein
R. M. Wells
P. Wilcox
Alina Wilhelm
D. A. Williams
T. J. Williamson
B. Zitzer
eng
uncontrolled
gamma rays: general
eng
uncontrolled
pulsars: general
eng
uncontrolled
stars: neutron
Physik
Institut für Physik und Astronomie
Referiert
Import
Green Open-Access
37685
2014
2014
eng
9
2
790
article
IOP Publ. Ltd.
Bristol
1
--
--
--
Very-high energy observations of the galactic center region by veritas IN 2010-2012
The Galactic center is an interesting region for high-energy (0.1-100 GeV) and very-high-energy (E > 100 GeV) gamma-ray observations. Potential sources of GeV/TeV gamma-ray emission have been suggested, e.g., the accretion of matter onto the supermassive black hole, cosmic rays from a nearby supernova remnant (e.g., Sgr A East), particle acceleration in a plerion, or the annihilation of dark matter particles. The Galactic center has been detected by EGRET and by Fermi/LAT in the MeV/GeV energy band. At TeV energies, the Galactic center was detected with moderate significance by the CANGAROO and Whipple 10 m telescopes and with high significance by H.E.S.S., MAGIC, and VERITAS. We present the results from three years of VERITAS observations conducted at large zenith angles resulting in a detection of the Galactic center on the level of 18 standard deviations at energies above similar to 2.5 TeV. The energy spectrum is derived and is found to be compatible with hadronic, leptonic, and hybrid emission models discussed in the literature. Future, more detailed measurements of the high-energy cutoff and better constraints on the high-energy flux variability will help to refine and/or disentangle the individual models.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/790/2/149
0004-637X
1538-4357
wos:2014
149
WOS:000339115800066
Archer, A (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA., beilicke@physics.wustl.edu
U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the UK
A. Archer
Anna Barnacka
M. Beilicke
W. Benbow
K. Berger
R. Bird
Jonathan Biteau
J. H. Buckley
V. Bugaev
K. Byrum
J. V. Cardenzana
M. Cerruti
W. Chen
Xiaoming Chen
L. Ciupik
M. P. Connolly
W. Cui
H. J. Dickinson
J. Dumm
J. D. Eisch
A. Falcone
Simone Federici
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
N. Galante
S. Griffin
S. T. Griffiths
J. Grube
G. Gyuk
Nils Hakansson
D. Hanna
J. Holder
G. Hughes
C. A. Johnson
P. Kaaret
P. Kar
M. Kertzman
Y. Khassen
D. Kieda
H. Krawczynski
S. Kumar
M. J. Lang
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
N. Park
J. S. Perkins
Manuela Pohl
A. Popkow
H. Prokoph
Elisa Pueschel
J. Quinn
K. Ragan
J. Rajotte
L. C. Reyes
P. T. Reynolds
G. T. Richards
E. Roache
G. H. Sembroski
K. Shahinyan
A. W. Smith
D. Staszak
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
A. Varlotta
S. Vincent
S. P. Wakely
A. Weinstein
R. Welsing
Alina Wilhelm
D. A. Williams
A. Zajczyk
B. Zitzer
eng
uncontrolled
astroparticle physics
eng
uncontrolled
black hole physics
eng
uncontrolled
Galaxy: center
eng
uncontrolled
gamma rays: galaxies
eng
uncontrolled
methods: data analysis
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert
46335
2017
2017
eng
2117
2123
7
471
article
Oxford Univ. Press
Oxford
1
--
--
--
Very-High-Energy gamma-Ray Observations of the Blazar 1ES 2344+514 with VERITAS
We present very-high-energy gamma-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance above the background of 20.8 sigma in 47.2 h (livetime) of observations, making this the most comprehensive very-high-energy study of 1ES 2344+514 to date. Using these observations, the temporal properties of 1ES 2344+514 are studied on short and long times-scales. We fit a constant-flux model to nightly and seasonally binned light curves and apply a fractional variability test to determine the stability of the source on different time-scales. We reject the constant-flux model for the 2007-2008 and 2014-2015 nightly binned light curves and for the long-term seasonally binned light curve at the > 3 sigma level. The spectra of the time-averaged emission before and after correction for attenuation by the extragalactic background light are obtained. The observed time-averaged spectrum above 200 GeV is satisfactorily fitted (x(2)/NDF = 7.89/6) by a power-law function with an index Gamma = 2.46 +/- 0.06(stat) +/- 0.20(sys) and extends to at least 8 TeV. The extragalactic-backgroundlight-deabsorbed spectrum is adequately fit (x(2)/NDF = 6.73/6) by a power-law function with an index Gamma = 2.15 +/- 0.06(stat) +/- 0.20(sys) while an F-test indicates that the power law with an exponential cut-off function provides a marginally better fit (x(2)/NDF = 2.56/5) at the 2.1 sigma level. The source location is found to be consistent with the published radio location and its spatial extent is consistent with a point source.
Monthly notices of the Royal Astronomical Society
10.1093/mnras/stx1756
0035-8711
1365-2966
wos:2017
WOS:000409022700057
obrien.stephan@gmail.com
U.S. Department of Energy Office of Science; U.S. National Science Foundation; Smithsonian Institution; NSERC in Canada; UCD
importub
2020-04-20T00:37:01+00:00
filename=package.tar
3355e527c386144045d7498762f18615
C. Allen
S. Archambault
A. Archer
W. Benbow
R. Bird
E. Bourbeau
Robert Brose
M. Buchovecky
J. H. Buckley
V. Bugaev
J. V. Cardenzana
M. Cerruti
Xuhui Chen
J. L. Christiansen
M. P. Connolly
W. Cui
M. K. Daniel
J. D. Eisch
Abe Falcone
Q. Feng
M. Fernandez-Alonso
J. P. Finley
H. Fleischhack
A. Flinders
L. Fortson
A. Furniss
G. H. Gillanders
S. Griffin
J. Grube
M. Huetten
N. Hakansson
D. Hanna
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
F. Krennrich
S. Kumar
M. J. Lang
G. Maier
S. McArthur
A. McCann
K. Meagher
P. Moriarty
R. Mukherjee
T. Nguyen
D. Nieto
R. A. Ong
A. N. Otte
N. Park
A. Petrashyk
A. Pichel
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
A. C. Rovero
C. Rulten
I. Sadeh
Marcos Santander
G. H. Sembroski
K. Shahinyan
Igor O. Telezhinsky
J. V. Tucci
J. Tyler
S. P. Wakely
A. Weinstein
Alina Wilhelm
D. A. Williams
eng
uncontrolled
astroparticle physics
eng
uncontrolled
BL Lacertae objects: individual: 1ES 2344+514=VERJ2347+517
eng
uncontrolled
gamma-rays: galaxies
Institut für Physik und Astronomie
Referiert
Import
55339
2017
2017
eng
8
1
836
article
IOP Publ. Ltd.
Bristol
1
2017-02-06
2017-02-06
--
Gamma-ray Observations of Tycho's Supernova Remnant with VERITAS and Fermi
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.3847/1538-4357/836/1/23
0004-637X
1538-4357
wos:2017
23
WOS:000397299000006
Park, N (reprint author), Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA., nahee@uchicago.edu
2022-06-27T06:10:45+00:00
sword
importub
filename=package.tar
5748de5e6796319a35295752092899cb
false
true
S. Archambault
A. Archer
Wystan Benbow
Ralph Bird
E. Bourbeau
M. Buchovecky
J. H. Buckley
V. Bugaev
M. Cerruti
M. P. Connolly
W. Cui
Vikram V. Dwarkadas
M. Errando
A. Falcone
Q. Feng
J. P. Finley
H. Fleischhack
L. Fortson
A. Furniss
S. Griffin
M. Huetten
D. Hanna
J. Holder
C. A. Johnson
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
S. Kumar
M. J. Lang
G. Maier
S. McArthur
A. McCann
P. Moriarty
R. Mukherjee
D. Nieto
R. A. Ong
A. N. Otte
Nahee Park
Martin Pohl
A. Popkow
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
I. Sadeh
M. Santander
G. H. Sembroski
K. Shahinyan
P. Slane
D. Staszak
Igor O. Telezhinsky
S. Trepanier
J. Tyler
S. P. Wakely
A. Weinstein
T. Weisgarber
P. Wilcox
Alina Wilhelm
D. A. Williams
B. Zitzer
eng
uncontrolled
material
eng
uncontrolled
data behind figure
Physik
Institut für Physik und Astronomie
Referiert
Import
49197
2019
2019
eng
511
516
6
6
3
article
Nature Publ. Group
London
1
--
2019-04-15
--
Direct measurement of stellar angular diameters by the VERITAS Cherenkov telescopes
The angular size of a star is a critical factor in determining its basic properties1. Direct measurement of stellar angular diameters is difficult: at interstellar distances stars are generally too small to resolve by any individual imaging telescope. This fundamental limitation can be overcome by studying the diffraction pattern in the shadow cast when an asteroid occults a star2, but only when the photometric uncertainty is smaller than the noise added by atmospheric scintillation3. Atmospheric Cherenkov telescopes used for particle astrophysics observations have not generally been exploited for optical astronomy due to the modest optical quality of the mirror surface. However, their large mirror area makes them well suited for such high-time-resolution precision photometry measurements4. Here we report two occultations of stars observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS)5 Cherenkov telescopes with millisecond sampling, from which we are able to provide a direct measurement of the occulted stars’ angular diameter at the ≤0.1 mas scale. This is a resolution never achieved before with optical measurements and represents an order of magnitude improvement over the equivalent lunar occultation method6. We compare the resulting stellar radius with empirically derived estimates from temperature and brightness measurements, confirming the latter can be biased for stars with ambiguous stellar classifications.
Nature astronomy
10.1038/s41550-019-0741-z
2397-3366
wos:2019
WOS:000470757700016
Daniel, MK (reprint author), Fred Lawrence Whipple Obser, Ctr Astrophys Harvard & Smithsonian, Amado, AZ 85645 USA., michael.daniel@cfa.harvard.edu; tarek.hassan@desy.de
US Department of Energy Office of ScienceUnited States Department of Energy (DOE); US National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada; Young Investigators Program of the Helmholtz Association
2021-02-01T12:31:33+00:00
sword
importub
filename=package.tar
d43b15ca5cae668dd8b4311d4cb40e1b
Daniel, M. K.
Hassan, Tarek
false
true
W. Benbow
R. Bird
A. Brill
Robert Brose
A. J. Chromey
M. K. Daniel
Q. Feng
J. P. Finley
L. Fortson
A. Furniss
G. H. Gillanders
C. Giuri
O. Gueta
D. Hanna
J. P. Halpern
Tarek Hassan
J. Holder
G. Hughes
T. B. Humensky
Amy M. Joyce
P. Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
D. Kieda
M. Krause
M. J. Lang
T. T. Y. Lin
Gernot Maier
N. Matthews
P. Moriarty
R. Mukherjee
D. Nieto
M. Nievas-Rosillos
R. A. Ong
N. Park
A. Petrashyk
Martin Pohl
Elisa Pueschel
John Quinn
K. Ragan
P. T. Reynolds
G. T. Richards
E. Roache
C. Rulten
Iftach Sadeh
M. Santander
G. H. Sembroski
K. Shahinyan
Iurii Sushch
S. P. Wakely
R. M. Wells
P. Wilcox
Alina Wilhelm
David A. Williams
T. J. Williamson
Physik
Institut für Physik und Astronomie
Referiert
Import
Green Open-Access
52485
2018
2018
eng
6
2
861
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration
1
2018-07-12
2018-07-12
--
VERITAS Observations of the BL Lac Object TXS 0506+056
On 2017 September 22, the IceCube Neutrino Observatory reported the detection of the high-energy neutrino event IC 170922A, of potential astrophysical origin. It was soon determined that the neutrino direction was consistent with the location of the gamma-ray blazar TXS 0506+056. (3FGL J0509.4+ 0541), which was in an elevated gamma-ray emission state as measured by the Fermi satellite. Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations of the neutrino/blazar region started on 2017 September 23 in response to the neutrino alert and continued through 2018 February 6. While no significant very-high-energy (VHE; E > 100 GeV) emission was observed from the blazar by VERITAS in the two-week period immediately following the IceCube alert, TXS 0506+ 056 was detected by VERITAS with a significance of 5.8 standard deviations (sigma) in the full 35 hr data set. The average photon flux of the source during this period was (8.9 +/- 1.6). x. 10(-12) cm(-2) s(-1), or 1.6% of the Crab Nebula flux, above an energy threshold of 110 GeV, with a soft spectral index of 4.8. +/-. 1.3.
The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
10.3847/2041-8213/aad053
2041-8205
2041-8213
wos:2018
L20
WOS:000438664500001
Santander, M (reprint author), Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA., jmsantander@ua.edu
U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); U.S. National Science FoundationNational Science Foundation (NSF); Smithsonian InstitutionSmithsonian Institution; NSERC in CanadaNatural Sciences and Engineering Research Council of Canada
2021-11-01T12:41:16+00:00
sword
importub
filename=package.tar
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A. U. Abeysekara
A. Archer
Wystan Benbow
Ralph Bird
A. Brill
Robert Brose
J. H. Buckley
Jessie L. Christiansen
A. J. Chromey
M. K. Daniel
A. Falcone
Qi Feng
John P. Finley
L. Fortson
Amy Furniss
Gerard H. Gillanders
O. Gueta
David Hanna
O. Hervet
J. Holder
G. Hughes
T. B. Humensky
Caitlin A. Johnson
Philip Kaaret
P. Kar
N. Kelley-Hoskins
M. Kertzman
David Kieda
Maria Krause
F. Krennrich
M. J. Lang
P. Moriarty
Reshmi Mukherjee
R. A. Ong
A. N. Otte
N. Park
A. Petrashyk
Martin Pohl
Elisa Pueschel
J. Quinn
K. Ragan
P. T. Reynolds
Gregory T. Richards
E. Roache
C. Rulten
I. Sadeh
Marcos Santander
S. S. Scott
G. H. Sembroski
Karlen Shahinyan
J. Tyler
S. P. Wakely
A. Weinstein
R. M. Wells
P. Wilcox
Alina Wilhelm
D. A. Williams
T. J. Williamson
B. Zitzer
A. Kaur
eng
uncontrolled
astroparticle physics
eng
uncontrolled
BL Lacertae objects: individual (TXS 0506+056, VER J0509+057)
eng
uncontrolled
gamma rays: galaxies
eng
uncontrolled
quasars: general
eng
uncontrolled
neutrinos
Physik
Institut für Physik und Astronomie
Referiert
Import
Green Open-Access