37044
2011
2011
eng
26
2
727
article
IOP Publ. Ltd.
Bristol
Fermi-LAT Collaboration, MAGIC Collaboration, VERITAS Collaboration
1
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Insights into the high-energy gamma-Ray emission of markarian 501 fromextensive multifrequency observations in the fermi era
We report on the gamma-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) gamma-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 +/- 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 +/- 0.14, and the softest one is 2.51 +/- 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size less than or similar to 0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (similar or equal to 10(44) erg s(-1)) constitutes only a small fraction (similar to 10(-3)) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/727/2/129
0004-637X
wos:2011-2013
129
WOS:000286662000068
Paneque, D (reprint author), Stanford Univ, Dept Phys, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA., dpaneque@mppmu.mpg.de; stawarz@astro.isas.jaxa.jp
K. A. Wallenberg Foundation; International Doctorate on Astroparticle
Physics (IDAPP) program; INFN Padova; Academy of Finland [212656,
210338]; National Radio Astronomy Observatory's Very Long Baseline Array
(VLBA) [BK150, BP143, MOJAVE]; Russian RFBR foundation [09-02-00092];
Georgian National Science Foundation [GNSF/ST07/4-180]; NASA
[NNX08AW31G]; NSF [AST-0808050]
A. A. Abdo
Margit Ackermann
M. Ajello
A. J. Allafort
L. Baldini
J. Ballet
G. Barbiellini
M. G. Baring
D. Bastieri
K. C. Bechtol
R. Bellazzini
B. Berenji
R. D. Blandford
E. D. Bloom
E. Bonamente
A. W. Borgland
A. Bouvier
T. J. Brandt
Johan Bregeon
A. Brez
M. Brigida
P. Bruel
R. Buehler
S. Buson
G. A. Caliandro
R. A. Cameron
A. Cannon
P. A. Caraveo
Svenja Carrigan
J. M. Casandjian
E. Cavazzuti
C. Cecchi
O. Celik
E. Charles
A. Chekhtman
C. C. Cheung
J. Chiang
S. Ciprini
R. Claus
J. Cohen-Tanugi
Jan Conrad
S. Cutini
C. D. Dermer
F. de Palma
E. do Couto e Silva
P. S. Drell
R. Dubois
D. Dumora
C. Favuzzi
S. J. Fegan
E. C. Ferrara
W. B. Focke
P. Fortin
M. Frailis
L. Fuhrmann
Y. Fukazawa
S. Funk
P. Fusco
F. Gargano
D. Gasparrini
N. Gehrels
S. Germani
N. Giglietto
F. Giordano
M. Giroletti
T. Glanzman
G. Godfrey
I. A. Grenier
L. Guillemot
S. Guiriec
M. Hayashida
E. Hays
D. Horan
R. E. Hughes
G. Johannesson
A. S. Johnson
W. N. Johnson
M. Kadler
T. Kamae
H. Katagiri
J. Kataoka
J. Knoedlseder
M. Kuss
J. Lande
L. Latronico
S. -H. Lee
M. Lemoine-Goumard
F. Longo
F. Loparco
B. Lott
M. N. Lovellette
P. Lubrano
G. M. Madejski
A. Makeev
W. Max-Moerbeck
Mario Nicola Mazziotta
J. E. McEnery
J. Mehault
P. F. Michelson
W. Mitthumsiri
T. Mizuno
A. A. Moiseev
C. Monte
M. E. Monzani
A. Morselli
I. V. Moskalenko
S. Murgia
M. Naumann-Godo
S. Nishino
P. L. Nolan
J. P. Norris
E. Nuss
T. Ohsugi
A. Okumura
N. Omodei
E. Orlando
J. F. Ormes
D. Paneque
J. H. Panetta
D. Parent
V. Pavlidou
T. J. Pearson
V. Pelassa
M. Pepe
M. Pesce-Rollins
F. Piron
T. A. Porter
S. Raino
R. Rando
M. Razzano
A. Readhead
A. Reimer
O. Reimer
J. L. Richards
J. Ripken
S. Ritz
M. Roth
H. F. -W. Sadrozinski
D. Sanchez
A. Sander
J. D. Scargle
C. Sgro
E. J. Siskind
P. D. Smith
G. Spandre
P. Spinelli
L. Stawarz
M. Stevenson
M. S. Strickman
K. V. Sokolovsky
D. J. Suson
H. Takahashi
T. Takahashi
T. Tanaka
J. B. Thayer
J. G. Thayer
D. J. Thompson
L. Tibaldo
F. Torres
G. Tosti
A. Tramacere
Y. Uchiyama
T. L. Usher
J. Vandenbroucke
V. Vasileiou
N. Vilchez
V. Vitale
A. P. Waite
P. Wang
A. E. Wehrle
B. L. Winer
K. S. Wood
Z. Yang
T. Ylinen
J. A. Zensus
M. Ziegler
J. Aleksic
L. A. Antonelli
P. Antoranz
Michael Backes
J. A. Barrio
J. Becerra Gonzalez
W. Bednarek
A. Berdyugin
K. Berger
E. Bernardini
A. Biland
O. Blanch Bigas
R. K. Bock
A. Boller
G. Bonnoli
Pol Bordas
D. Borla Tridon
Valentin Bosch-Ramon
D. Bose
I. Braun
T. Bretz
M. Camara
E. Carmona
A. Carosi
P. Colin
E. Colombo
J. L. Contreras
J. Cortina
S. Covino
F. Dazzi
A. de Angelis
E. De Cea del Pozo
B. De Lotto
M. De Maria
F. De Sabata
C. Delgado Mendez
A. Diago Ortega
M. Doert
A. Dominguez
Dijana Dominis Prester
D. Dorner
M. Doro
D. Elsaesser
D. Ferenc
M. V. Fonseca
L. Font
R. J. Garcia Lopen
M. Garczarczyk
M. Gaug
G. Giavitto
N. Godinovi
D. Hadasch
A. Herrero
D. Hildebrand
D. Hoehne-Moench
J. Hose
D. Hrupec
T. Jogler
S. Klepser
T. Kraehenbuehl
D. Kranich
J. Krause
A. La Barbera
E. Leonardo
E. Lindfors
S. Lombardi
M. Lopez
E. Lorenz
P. Majumdar
E. Makariev
G. Maneva
N. Mankuzhiyil
K. Mannheim
L. Maraschi
M. Mariotti
M. Martinez
D. Mazin
M. Meucci
J. M. Miranda
R. Mirzoyan
H. Miyamoto
J. Moldon
A. Moralejo
D. Nieto
K. Nilsson
R. Orito
I. Oya
R. Paoletti
J. M. Paredes
S. Partini
M. Pasanen
F. Pauss
R. G. Pegna
M. A. Perez-Torres
M. Persic
J. Peruzzo
J. Pochon
P. G. Prada Moroni
F. Prada
E. Prandini
N. Puchades
I. Puljak
T. Reichardt
R. Reinthal
W. Rhode
M. Ribo
J. Rico
M. Rissi
S. Ruegamer
A. Saggion
K. Saito
T. Y. Saito
M. Salvati
M. Sanchez-Conde
K. Satalecka
V. Scalzotto
V. Scapin
C. Schultz
T. Schweizer
M. Shayduk
S. N. Shore
A. Sierpowska-Bartosik
A. Sillanpaa
J. Sitarek
D. Sobczynska
F. Spanier
S. Spiro
A. Stamerra
B. Steinke
J. Storz
N. Strah
J. C. Struebig
T. Suric
L. O. Takalo
F. Tavecchio
P. Temnikov
T. Terzic
D. Tescaro
M. Teshima
H. Vankov
R. M. Wagner
Q. Weitzel
V. Zabalza
F. Zandanel
R. Zanin
V. A. Acciari
T. Arlen
T. Aune
W. Benbow
D. Boltuch
S. M. Bradbury
J. H. Buckley
V. Bugaev
A. Cannon
A. Cesarini
L. Ciupik
W. Cui
R. Dickherber
M. Errando
A. Falcone
J. P. Finley
G. Finnegan
L. Fortson
A. Furniss
N. Galante
D. Gall
G. H. Gillanders
S. Godambe
J. Grube
R. Guenette
G. Gyuk
D. Hanna
J. Holder
D. Huang
C. M. Hui
T. B. Humensky
P. Kaaret
N. Karlsson
M. Kertzman
D. Kieda
A. Konopelko
H. Krawczynski
F. Krennrich
M. J. Lang
G. Maier
S. McArthur
A. McCann
M. McCutcheon
P. Moriarty
R. Mukherjee
R. Ong
N. Otte
D. Pandel
J. S. Perkins
A. Pichel
M. Pohl
J. Quinn
K. Ragan
L. C. Reyes
P. T. Reynolds
E. Roache
H. J. Rose
A. C. Rovero
M. Schroedter
G. H. Sembroski
G. D. Senturk
D. Steele
S. P. Swordy
G. Tesic
M. Theiling
S. Thibadeau
A. Varlotta
S. Vincent
S. P. Wakely
J. E. Ward
T. C. Weekes
A. Weinstein
T. Weisgarber
D. A. Williams
M. Wood
B. Zitzer
M. Villata
C. M. Raiteri
H. D. Aller
M. F. Aller
A. A. Arkharov
D. A. Blinov
P. Calcidese
W. P. Chen
N. V. Efimova
G. Kimeridze
T. S. Konstantinova
E. N. Kopatskaya
E. Koptelova
O. M. Kurtanidze
S. O. Kurtanidze
A. Lahteenmaki
V. M. Larionov
E. G. Larionova
L. V. Larionova
R. Ligustri
D. A. Morozova
M. G. Nikolashvili
L. A. Sigua
I. S. Troitsky
E. Angelakis
M. Capalbi
A. Carraminana
L. Carrasco
P. Cassaro
E. de la Fuente
M. A. Gurwell
Y. Y. Kovalev
Yu. A. Kovalev
T. P. Krichbaum
H. A. Krimm
Paolo Leto
M. L. Lister
G. Maccaferri
J. W. Moody
Y. Mori
I. Nestoras
A. Orlati
C. Pagani
C. Pace
R. Pearson
M. Perri
B. G. Piner
A. B. Pushkarev
E. Ros
A. C. Sadun
T. Sakamoto
M. Tornikoski
Y. Yatsu
A. Zook
eng
uncontrolled
acceleration of particles
eng
uncontrolled
BL Lacertae objects: general
eng
uncontrolled
BL Lacertae objects: individual (Mrk 501)
eng
uncontrolled
galaxies: active
eng
uncontrolled
gamma rays: general
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert
36797
2011
2011
eng
9
1
734
article
IOP Publ. Ltd.
Bristol
1
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Observations of the young supernova remnant RX J1713.7-3946 with the fermi large area telescope
We present observations of the young supernova remnant (SNR) RX J1713.7-3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0 degrees.55 +/- 0 degrees.04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7-3946. The spectrum of the source can be described by a very hard power law with a photon index of Gamma = 1.5 +/- 0.1 that coincides in normalization with the steeper H. E. S. S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.
The astrophysical journal : an international review of spectroscopy and astronomical physics
10.1088/0004-637X/734/1/28
0004-637X
wos:2011-2013
28
WOS:000291026900028
Abdo, AA (reprint author), George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA., markusa@slac.stanford.edu; funk@slac.stanford.edu; uchiyama@slac.stanford.edu
K. A. Wallenberg Foundation; European Community [ERC-StG-259391];
International Doctorate on Astroparticle Physics (IDAPP) program
A. A. Abdo
Margit Ackermann
M. Ajello
A. J. Allafort
L. Baldini
J. Ballet
G. Barbiellini
M. G. Baring
D. Bastieri
R. Bellazzini
B. Berenji
R. D. Blandford
E. D. Bloom
E. Bonamente
A. W. Borgland
A. Bouvier
T. J. Brandt
Johan Bregeon
M. Brigida
P. Bruel
R. Buehler
S. Buson
G. A. Caliandro
R. A. Cameron
P. A. Caraveo
J. M. Casandjian
C. Cecchi
S. Chaty
A. Chekhtman
C. C. Cheung
J. Chiang
A. N. Cillis
S. Ciprini
R. Claus
J. Cohen-Tanugi
Jan Conrad
S. Corbel
S. Cutini
A. de Angelis
F. de Palma
C. D. Dermer
S. W. Digel
E. do Couto e Silva
P. S. Drell
A. Drlica-Wagner
R. Dubois
D. Dumora
C. Favuzzi
E. C. Ferrara
P. Fortin
M. Frailis
Y. Fukazawa
Y. Fukui
S. Funk
P. Fusco
F. Gargano
D. Gasparrini
N. Gehrels
S. Germani
N. Giglietto
F. Giordano
M. Giroletti
T. Glanzman
G. Godfrey
I. A. Grenier
M. -H. Grondin
S. Guiriec
D. Hadasch
Y. Hanabata
A. K. Harding
M. Hayashida
K. Hayashi
E. Hays
D. Horan
M. S. Jackson
G. Johannesson
A. S. Johnson
T. Kamae
H. Katagiri
J. Kataoka
M. Kerr
J. Knoedlseder
M. Kuss
J. Lande
L. Latronico
S. -H. Lee
M. Lemoine-Goumard
F. Longo
F. Loparco
M. N. Lovellette
P. Lubrano
G. M. Madejski
A. Makeev
Mario Nicola Mazziotta
J. E. McEnery
P. F. Michelson
R. P. Mignani
W. Mitthumsiri
T. Mizuno
A. A. Moiseev
C. Monte
M. E. Monzani
A. Morselli
I. V. Moskalenko
S. Murgia
M. Naumann-Godo
P. L. Nolan
J. P. Norris
E. Nuss
T. Ohsugi
A. Okumura
E. Orlando
J. F. Ormes
D. Paneque
D. Parent
V. Pelassa
M. Pesce-Rollins
M. Pierbattista
F. Piron
Martin Pohl
T. A. Porter
S. Raino
R. Rando
M. Razzano
O. Reimer
T. Reposeur
S. Ritz
R. W. Romani
M. Roth
H. F. -W. Sadrozinski
P. M. Saz Parkinson
C. Sgro
D. A. Smith
P. D. Smith
G. Spandre
P. Spinelli
M. S. Strickman
H. Tajima
H. Takahashi
T. Takahashi
T. Tanaka
J. G. Thayer
J. B. Thayer
D. J. Thompson
L. Tibaldo
O. Tibolla
D. F. Torres
G. Tosti
A. Tramacere
E. Troja
Y. Uchiyama
J. Vandenbroucke
V. Vasileiou
G. Vianello
N. Vilchez
V. Vitale
A. P. Waite
P. Wang
B. L. Winer
K. S. Wood
H. Yamamoto
R. Yamazaki
Z. Yang
M. Ziegler
eng
uncontrolled
acceleration of particles
eng
uncontrolled
gamma rays: general
eng
uncontrolled
gamma rays: ISM
eng
uncontrolled
ISM: individual objects (RX J1713.7-3946)
eng
uncontrolled
ISM: supernova remnants
eng
uncontrolled
radiation mechanisms: non-thermal
Institut für Physik und Astronomie
Referiert