EARLY FERMI GAMMA-RAY SPACE TELESCOPE OBSERVATIONS OF THE QUASAR 3C 454.3

Abdo AA, Ackermann M, Ajello M, Atwood WB, Axelsson M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Battelino M, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Bouvier A, Bregeon J, Brez A, Brigida M, Bruel P, Burnett TH, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cavazzuti E, Cecchi C, Charles E, Chaty S, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Cominsky LR, Conrad J, Costamante L, Cutini S, Dermer CD, De Angelis A, De Palma F, Digel SW, Do Couto E Silva E, Donato D, Drell PS, Dubois R, Dumora D, Farnier C, Favuzzi C, Focke WB, Foschini L, Frailis M, Fuhrmann L, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giebels B, Giglietto N, Giommi P, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Hanabata Y, Harding AK, Hartman RC, Hayashida M, Hays E, Hughes RE, Johannesson G, Johnson AS, Johnson RP, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kawai N, Kerr M, Knoedlseder J, Kocian ML, Kuehn F, Kuss MW, Latronico L, Lee SH, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Massaro E, Mazziotta MN, Mcenery JE, Mcglynn S, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes JF, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Porter TA, Raino S, Rando R, Razzano M, Reimer A, Reimer O, Reposeur T, Reyes LC, Ritz S, Rochester LS, Rodriguez AY, Rahoui F, Ryde F, Sadrozinski HFW, Sambruna R, Sanchez D, Sander A, Parkinson PMS, Sgro C, Shaw MS, Smith DA, Smith PD, Spandre G, Spinelli P, Starck JL, Strickman MS, Suson DJ, Tajima H, Takahashi HH, Takahashi T, Tanaka T, Thayer JB, Thayer JG, Thompson DJ, Tibaldo L, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Vilchez N, Villata M, Vitale V, Waite AP, Winer BL, Wood KS, Ylinen T, Zensus JA, Ziegler M (2009)

Publication Type: Journal article

Publication year: 2009

Journal

Book Volume: 699

Pages Range: 817-823

Journal Issue: 1

DOI: 10.1088/0004-637X/699/1/817

Abstract

This is the first report of Fermi Gamma-Ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope, covering 2008 July 7-October 6, indicate strong, highly variable.-ray emission with an average flux of similar to 3 x 10 (6) photons cm(-2) s(-1), for energies > 100 MeV. The gamma-ray flux is variable, with strong, distinct, symmetrically shaped flares for which the flux increases by a factor of several on a timescale of about 3 days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair production implies relativistic beaming with Doppler factor delta > 8, consistent with the values inferred from Very Long Baseline Interferometry observations of superluminal expansion (delta similar to 25). The observed gamma-ray spectrum is not consistent with a simple power law, but instead steepens strongly above similar to 2 GeV, and is well described by a broken power law with photon indices of similar to 2.3 and similar to 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high-luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2 GeV could be due to gamma-ray absorption via photon-photon pair production on the soft X-ray photon field of the host active galactic nucleus, but such an interpretation would require the dissipation region to be located very close (less than or similar to 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

Authors with CRIS profile

Involved external institutions

U.S. Naval Research Laboratory United States (USA) (US) Stanford University United States (USA) (US) University of California Santa Cruz United States (USA) (US) The Oskar Klein Centre Sweden (SE) National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) Italy (IT) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot France (FR) Ohio State University United States (USA) (US) University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro Italy (IT) University of Washington United States (USA) (US) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) Italy (IT) Italian Space Agency / Agenzia Spaziale Italiana (ASI) Italy (IT) University of Montpellier / Université Montpellier France (FR) Sonoma State University United States (USA) (US) Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) Sweden (SE) University of Udine / Università degli Studi di Udine Italy (IT) Université Bordeaux 1, Sciences et Technologies France (FR) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy Germany (DE) Hiroshima University Japan (JP) University of Maryland United States (USA) (US) École Polytechnique - Université Paris-Saclay France (FR) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) Spain (ES) University of Alabama in Huntsville (UAH) United States (USA) (US) Waseda University / 早稲田大学 Japan (JP) Riken Institute of Physical and Chemical Research / 理研 Japan (JP) National Center for Scientific Research / Centre national de la recherche scientifique (CNRS) France (FR) Università degli studi "La Sapienza" Italy (IT) University of Denver United States (USA) (US) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics Germany (DE) University of Chicago United States (USA) (US) Purdue University Northwest / Purdue University Calumet United States (USA) (US) Japan Aerospace eXploration Agency (JAXA) Japan (JP)

How to cite

APA:

Abdo, A.A., Ackermann, M., Ajello, M., Atwood, W.B., Axelsson, M., Baldini, L.,... Ziegler, M. (2009). EARLY FERMI GAMMA-RAY SPACE TELESCOPE OBSERVATIONS OF THE QUASAR 3C 454.3. Astrophysical Journal, 699(1), 817-823. https://dx.doi.org/10.1088/0004-637X/699/1/817

MLA:

Abdo, A. A., et al. "EARLY FERMI GAMMA-RAY SPACE TELESCOPE OBSERVATIONS OF THE QUASAR 3C 454.3." Astrophysical Journal 699.1 (2009): 817-823.

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