35500
2012
2012
eng
13
2
760
article
IOP Publ. Ltd.
Bristol
1
--
--
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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
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
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
38010
2014
2014
eng
9
1
783
article
IOP Publ. Ltd.
Bristol
1
--
--
--
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
37289
2014
2014
eng
11
2
797
article
IOP Publ. Ltd.
Bristol
Veritas Collaboration
1
--
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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
39386
2015
2015
eng
12
573
article
EDP Sciences
Les Ulis
MAGIC Collaboration, VERITAS Collaboration
1
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--
--
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
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
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
35214
2013
2013
eng
9
1
764
article
IOP PUBLISHING LTD
BRISTOL
1
--
--
--
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)
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
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
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
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
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
34931
2013
2013
eng
7
2
770
article
IOP Publ. Ltd.
Bristol
1
--
--
--
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
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
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
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
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
36823
2011
2011
eng
10
2
733
article
IOP Publ. Ltd.
Bristol
1
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--
--
Gamma-ray observations of the Be/Pulsar binary 1A 0535+262 during a Giant X-Ray outburst
Giant X-ray outbursts, with luminosities of about 10(37) erg s(-1), are observed roughly every five years from the nearby Be/pulsar binary 1A 0535+262. In this article, we present observations of the source with VERITAS at very high energies (VHEs; E > 100 GeV) triggered by the X-ray outburst in 2009 December. The observations started shortly after the onset of the outburst and provided comprehensive coverage of the episode, as well as the 111 day binary orbit. No VHE emission is evident at any time. We also examined data from the contemporaneous observations of 1A 0535+262 with the Fermi/Large Area Telescope at high-energy photons (E > 0.1 GeV) and failed to detect the source at GeV energies. The X-ray continua measured with the Swift/X-Ray Telescope and the RXTE/PCA can be well described by the combination of blackbody and Comptonized emission from thermal electrons. Therefore, the gamma-ray and X-ray observations suggest the absence of a significant population of non-thermal particles in the system. This distinguishes 1A 0535+262 from those Be X-ray binaries (such as PSR B1259-63 and LS I +61 degrees 303) that have been detected at GeV-TeV energies. We discuss the implications of the results on theoretical models.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/733/2/96
0004-637X
wos:2011-2013
96
WOS:000290676100023
Cui, W (reprint author), Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA., avarlott@purdue.edu; cui@purdue.edu; gernot.maier@desy.de; avarlott@purdue.edu
US Department of Energy; US National Science Foundation; Smithsonian
Institution; NSERC in Canada; Science Foundation Ireland; STFC in the
UK; Helmholtz Association; NASA; Purdue University
V. A. Acciari
E. Aliu
M. Araya
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
A. Falcone
J. P. Finley
L. Fortson
A. Furniss
N. Galante
D. Gall
S. Godambe
S. Griffin
R. Guenette
G. Gyuk
D. Hanna
J. Holder
G. Hughes
C. M. Hui
T. B. Humensky
A. Imran
P. Kaaret
M. Kertzman
H. Krawczynski
F. Krennrich
A. S. Madhavan
G. Maier
P. Majumdar
S. McArthur
P. Moriarty
R. A. Ong
A. N. Otte
D. Pandel
N. Park
J. S. Perkins
Martin Pohl
H. Prokoph
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
D. B. Saxon
G. H. Sembroski
G. D. Sentuerk
A. W. Smith
G. Tesic
M. Theiling
S. Thibadeau
A. Varlotta
S. Vincent
M. Vivier
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
S. Weng
D. A. Williams
M. Wood
B. Zitzer
eng
uncontrolled
acceleration of particles
eng
uncontrolled
binaries: general
eng
uncontrolled
gamma rays: general
eng
uncontrolled
stars: individual (1A 0535+262)
Institut für Physik und Astronomie
Referiert
37935
2014
2014
eng
8
1
785
article
IOP Publ. Ltd.
Bristol
VERITAS Collaboration, Fermi LAT Collaboration
1
--
--
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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
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--
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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
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
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
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
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
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
36045
2012
2012
eng
12
6
85
article
American Physical Society
College Park
1
--
--
--
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
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
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
36552
2011
2011
eng
69
72
4
6052
334
article
American Assoc. for the Advancement of Science
Washington
VERITAS Collaboration
1
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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
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