INSIGHTS INTO THE HIGH-ENERGY γ-RAY EMISSION OF MARKARIAN 501 FROM EXTENSIVE MULTIFREQUENCY OBSERVATIONS IN THE FERMI ERA

被引:183
作者
Abdo, A. A. [3 ,4 ]
Ackermann, M. [1 ,2 ]
Ajello, M. [1 ,2 ]
Allafort, A. [1 ,2 ]
Baldini, L. [5 ]
Ballet, J. [6 ]
Barbiellini, G. [7 ,8 ]
Baring, M. G. [9 ]
Bastieri, D. [10 ,11 ]
Bechtol, K. [1 ,2 ]
Bellazzini, R. [5 ]
Berenji, B. [1 ,2 ]
Blandford, R. D. [1 ,2 ]
Bloom, E. D. [1 ,2 ]
Bonamente, E. [12 ,13 ]
Borgland, A. W. [1 ,2 ]
Bouvier, A. [1 ,2 ]
Brandt, T. J. [14 ,15 ]
Bregeon, J. [5 ]
Brez, A. [5 ]
Brigida, M. [16 ,17 ,18 ]
Bruel, P. [19 ]
Buehler, R. [1 ,2 ]
Buson, S. [10 ,11 ]
Caliandro, G. A. [20 ]
Cameron, R. A. [1 ,2 ]
Cannon, A. [21 ,22 ]
Caraveo, P. A. [23 ]
Carrigan, S. [11 ]
Casandjian, J. M. [6 ]
Cavazzuti, E. [24 ]
Cecchi, C. [12 ,13 ]
Celik, O. . [21 ,25 ,26 ,27 ]
Charles, E. [1 ,2 ]
Chekhtman, A. [3 ,28 ]
Cheung, C. C. [3 ,4 ]
Chiang, J. [1 ,2 ]
Ciprini, S. [13 ]
Claus, R. [1 ,2 ]
Cohen-Tanugi, J. [29 ]
Conrad, J. [30 ,31 ,141 ]
Cutini, S. [24 ]
Dermer, C. D. [3 ]
de Palma, F. [16 ,17 ,18 ]
do Couto e Silva, E. [1 ,2 ]
Drell, P. S. [1 ,2 ]
Dubois, R. [1 ,2 ]
Dumora, D. [32 ]
Favuzzi, C. [16 ,17 ,18 ]
Fegan, S. J. [19 ]
机构
[1] Stanford Univ, Dept Phys, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA
[2] Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA
[3] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA
[4] Natl Acad Sci, Natl Res Council Res Associate, Washington, DC 20001 USA
[5] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy
[6] Univ Paris Diderot, Serv Astrophys, CEA Saclay, Lab AIM,CEA IRFU,CNRS, F-91191 Gif Sur Yvette, France
[7] Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy
[8] Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy
[9] Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA
[10] Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy
[11] Univ Padua, Dipartimento Fis G Galilei, I-35131 Padua, Italy
[12] Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy
[13] Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy
[14] CNRS UPS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France
[15] Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA
[16] M Merlin Univ, Dipartimento Fis, I-70126 Bari, Italy
[17] Politecn Bari, I-70126 Bari, Italy
[18] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy
[19] CNRS, IN2P3, Lab Leprince Ringuet, Ecole Polytech, Palaiseau, France
[20] Inst Ciencies Espai IEEC CSIC, Barcelona 08193, Spain
[21] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[22] Univ Coll Dublin, Dublin 4, Ireland
[23] Ist Astrofis Spaziale & Fis Cosm, INAF, I-20133 Milan, Italy
[24] ASI, Sci Data Ctr, I-00044 Rome, Italy
[25] CRESST, Greenbelt, MD 20771 USA
[26] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA
[27] Univ Maryland Baltimore Cty, Ctr Space Sci & Technol, Baltimore, MD 21250 USA
[28] George Mason Univ, Fairfax, VA 22030 USA
[29] Univ Montpellier 2, CNRS, IN2P3, Lab Phys Theor & Astroparticules, Montpellier, France
[30] Stockholm Univ, Dept Phys, SE-10691 Stockholm, Sweden
[31] Oskar Klein Ctr Cosmoparticle Phys, SE-10691 Stockholm, Sweden
[32] Univ Bordeaux 1, CNRS, IN2P3, Ctr Etud Nucl Bordeaux Gradignan, F-33175 Gradignan, France
[33] Univ Udine, Dipartimento Fis, I-33100 Udine, Italy
[34] Ist Nazl Fis Nucl, Sez Trieste, Grp Collegato Udine, I-33100 Udine, Italy
[35] Ist Nazl Astrofis, Osservatorio Astron Trieste, I-34143 Trieste, Italy
[36] Max Planck Inst Radioastron, D-53121 Bonn, Germany
[37] Hiroshima Univ, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan
[38] Ist Radioastron, INAF, I-40129 Bologna, Italy
[39] Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA
[40] Dr Remeis Sternwarte Bamberg, D-96049 Bamberg, Germany
[41] Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany
[42] Univ Space Res Assoc, Columbia, MD 21044 USA
[43] Waseda Univ, Res Inst Sci & Engn, Shinjuku Ku, Tokyo 1698555, Japan
[44] CALTECH, Cahill Ctr Astron & Astrophys, Pasadena, CA 91125 USA
[45] Univ Maryland, Dept Phys, College Pk, MD 20742 USA
[46] Univ Maryland, Dept Astron, College Pk, MD 20742 USA
[47] Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy
[48] Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA
[49] Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Higashihiroshima, Hiroshima 7398526, Japan
[50] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan
基金
美国国家科学基金会; 芬兰科学院;
关键词
acceleration of particles; BL Lacertae objects: general; BL Lacertae objects: individual (Mrk 501); galaxies: active; gamma rays: general; radiation mechanisms: non-thermal; CHERENKOV TELESCOPE SYSTEM; MAGNETOSONIC SHOCK-WAVES; LOG-PARABOLIC SPECTRA; LARGE-AREA TELESCOPE; X-RAY; PARTICLE-ACCELERATION; TEV VARIABILITY; MULTIWAVELENGTH OBSERVATIONS; ULTRARELATIVISTIC SHOCKS; TEMPORAL CHARACTERISTICS;
D O I
10.1088/0004-637X/727/2/129
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
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.
引用
收藏
页数:26
相关论文
共 122 条
[1]   FERMI LARGE AREA TELESCOPE FIRST SOURCE CATALOG [J].
Abdo, A. A. ;
Ackermann, M. ;
Ajello, M. ;
Allafort, A. ;
Antolini, E. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Bastieri, D. ;
Baughman, B. M. ;
Bechtol, K. ;
Bellazzini, R. ;
Belli, F. ;
Berenji, B. ;
Bisello, D. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonamente, E. ;
Bonnell, J. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Brigida, M. ;
Bruel, P. ;
Burnett, T. H. ;
Busetto, G. ;
Buson, S. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Campana, R. ;
Canadas, B. ;
Caraveo, P. A. ;
Carrigan, S. ;
Casandjian, J. M. ;
Cavazzuti, E. ;
Ceccanti, M. ;
Cecchi, C. ;
Celik, Oe. ;
Charles, E. ;
Chekhtman, A. ;
Cheung, C. C. ;
Chiang, J. ;
Cillis, A. N. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Conrad, J. .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2010, 188 (02) :405-436
[2]   THE SPECTRAL ENERGY DISTRIBUTION OF FERMI BRIGHT BLAZARS [J].
Abdo, A. A. ;
Ackermann, M. ;
Agudo, I. ;
Ajello, M. ;
Aller, H. D. ;
Aller, M. F. ;
Angelakis, E. ;
Arkharov, A. A. ;
Axelsson, M. ;
Bach, U. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Bastieri, D. ;
Baughman, B. M. ;
Bechtol, K. ;
Bellazzini, R. ;
Benitez, E. ;
Berdyugin, A. ;
Berenji, B. ;
Blandford, R. D. ;
Bloom, E. D. ;
Boettcher, M. ;
Bonamente, E. ;
Borgland, A. W. ;
Bregeon, J. ;
Brez, A. ;
Brigida, M. ;
Bruel, P. ;
Burnett, T. H. ;
Burrows, D. ;
Buson, S. ;
Caliandro, G. A. ;
Calzoletti, L. ;
Cameron, R. A. ;
Capalbi, M. ;
Caraveo, P. A. ;
Carosati, D. ;
Casandjian, J. M. ;
Cavazzuti, E. ;
Cecchi, C. ;
Celik, Oe. ;
Charles, E. ;
Chaty, S. ;
Chekhtman, A. ;
Chen, W. P. ;
Chiang, J. ;
Chincarini, G. ;
Ciprini, S. ;
Claus, R. .
ASTROPHYSICAL JOURNAL, 2010, 716 (01) :30-70
[3]   SPECTRAL PROPERTIES OF BRIGHT FERMI-DETECTED BLAZARS IN THE GAMMA-RAY BAND [J].
Abdo, A. A. ;
Ackermann, M. ;
Ajello, M. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Bastieri, D. ;
Bechtol, K. ;
Bellazzini, R. ;
Berenji, B. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonamente, E. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Brigida, M. ;
Bruel, P. ;
Burnett, T. H. ;
Buson, S. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Carrigan, S. ;
Casandjian, J. M. ;
Cavazzuti, E. ;
Cecchi, C. ;
Celik, Oe ;
Charles, E. ;
Chekhtman, A. ;
Cheung, C. C. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Conrad, J. ;
Cutini, S. ;
Dermer, C. D. ;
de Angelis, A. ;
de Palma, F. ;
Digel, S. W. ;
do Couto e Silva, E. ;
Drell, P. S. ;
Dubois, R. ;
Dumora, D. ;
Farnier, C. ;
Favuzzi, C. .
ASTROPHYSICAL JOURNAL, 2010, 710 (02) :1271-1285
[4]   EARLY FERMI GAMMA-RAY SPACE TELESCOPE OBSERVATIONS OF THE QUASAR 3C 454.3 [J].
Abdo, A. A. ;
Ackermann, M. ;
Ajello, M. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Bastieri, D. ;
Battelino, M. ;
Baughman, B. M. ;
Bechtol, K. ;
Bellazzini, R. ;
Berenji, B. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonamente, E. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Brigida, M. ;
Bruel, P. ;
Burnett, T. H. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Casandjian, J. M. ;
Cavazzuti, E. ;
Cecchi, C. ;
Charles, E. ;
Chaty, S. ;
Chekhtman, A. ;
Cheung, C. C. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Cominsky, L. R. ;
Conrad, J. ;
Costamante, L. ;
Cutini, S. ;
Dermer, C. D. ;
de Angelis, A. ;
de Palma, F. ;
Digel, S. W. ;
do Couto e Silva, E. ;
Donato, D. ;
Drell, P. S. ;
Dubois, R. .
ASTROPHYSICAL JOURNAL, 2009, 699 (01) :817-823
[5]   Veritas observations of the γ-ray binary LS I+61 303 [J].
Acciari, V. A. ;
Beilicke, M. ;
Blaylock, G. ;
Bradbury, S. M. ;
Buckley, J. H. ;
Bugaev, V. ;
Butt, Y. ;
Byrum, K. L. ;
Celik, O. ;
Cesarini, A. ;
Ciupik, L. ;
Chow, Y. C. K. ;
Cogan, P. ;
Colin, P. ;
Cui, W. ;
Daniel, M. K. ;
Duke, C. ;
Ergin, T. ;
Falcone, A. D. ;
Fegan, S. J. ;
Finley, J. P. ;
Fortin, P. ;
Fortson, L. F. ;
Gall, D. ;
Gibbs, K. ;
Gillanders, G. H. ;
Grube, J. ;
Guenette, R. ;
Hanna, D. ;
Hays, E. ;
Holder, J. ;
Horan, D. ;
Hughes, S. B. ;
Hui, C. M. ;
Humensky, T. B. ;
Kaaret, P. ;
Kieda, D. B. ;
Kildea, J. ;
Konopelko, A. ;
Krawczynski, H. ;
Krennrich, F. ;
Lang, M. J. ;
LeBohec, S. ;
Lee, K. ;
Maier, G. ;
McCann, A. ;
McCutcheon, M. ;
Millis, J. ;
Moriarty, P. ;
Mukherjee, R. .
ASTROPHYSICAL JOURNAL, 2008, 679 (02) :1427-1432
[6]  
Acciari V. A., 2011, APJ IN PRESS
[7]  
ACCIARI VA, 2010, APJ, V714, pA163
[8]   Particle acceleration by ultrarelativistic shocks: theory and simulations [J].
Achterberg, A ;
Gallant, YA ;
Kirk, JG ;
Guthmann, AW .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2001, 328 (02) :393-408
[9]  
Aharonian F, 1999, ASTRON ASTROPHYS, V349, P29
[10]   The TeV energy spectrum of Markarian 501 measured with the stereoscopic telescope system of HEGRA during 1998 and 1999 [J].
Aharonian, F ;
Akhperjanian, A ;
Barrio, J ;
Bernlöhr, K ;
Börst, H ;
Bojahr, H ;
Bolz, O ;
Contreras, J ;
Cortina, J ;
Denninghoff, S ;
Fonseca, V ;
Gonzalez, J ;
Götting, N ;
Heinzelmann, G ;
Hermann, G ;
Heusler, A ;
Hofmann, W ;
Horns, D ;
Iserlohe, C ;
Ibarra, A ;
Jung, I ;
Kankanyan, R ;
Kestel, M ;
Kettler, J ;
Kohnle, A ;
Konopelko, A ;
Kornmeyer, H ;
Kranich, D ;
Krawczynski, H ;
Lampeitl, H ;
Lorenz, E ;
Lucarelli, F ;
Magnussen, N ;
Mang, O ;
Meyer, H ;
Mirzoyan, R ;
Moralejo, A ;
Padilla, L ;
Panter, M ;
Plaga, R ;
Plyasheshnikov, A ;
Prahl, J ;
Pühlhofer, G ;
Röhring, A ;
Rhode, W ;
Rowell, GP ;
Sahakian, V ;
Samorski, M ;
Schilling, M ;
Schröder, F .
ASTROPHYSICAL JOURNAL, 2001, 546 (02) :898-902