FERMI LARGE AREA TELESCOPE VIEW OF THE CORE OF THE RADIO GALAXY CENTAURUS A

Abdo AA, Ackermann M, Ajello M, Atwood WB, Baldini L, Ballet J, Barbiellini G, Bastieri D, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Bouvier A, Brandt TJ, Bregeon J, Brez A, Brigida M, Bruel P, Buehler R, Buson S, Caliandro GA, Cameron RA, Cannon A, Caraveo PA, Carrigan S, Casandjian JM, Cavazzuti E, Cecchi C, Celik O, Charles E, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Colafrancesco S, Cominsky LR, Conrad J, Costamante L, Davis DS, Dermer CD, De Angelis A, De Palma F, Do Couto E Silva E, Drell PS, Dubois R, Dumora D, Falcone A, Farnier C, Favuzzi C, Fegan SJ, Finke J, Focke WB, Fortin P, Frailis M, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Georganopoulos M, Germani S, Giebels B, Giglietto N, Giommi P, Giordano F, Giroletti M, Glanzman T, Godfrey G, Grandi P, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Hadasch D, Harding AK, Hase H, Hayashida M, Hays E, Horan D, Hughes RE, Itoh R, Jackson MS, Johannesson G, Johnson AS, Johnson TJ, Johnson WN, Kadler M, Kamae T, Katagiri H, Kataoka J, Kawai N, Kishishita T, Knoedlseder J, Kuss MW, Lande J, Latronico L, Lee SH, Lemoine-Goumard M, Garde ML, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Makeev A, Mazziotta MN, Mcconville W, Mcenery JE, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Müller C, Nakamori T, Naumann-Godo M, Nolan PL, Norris JP, Nuss E, Ohno M, Ohsugi T, Ojha R, Okumura A, Omodei N, Orlando E, Ormes JF, Ozaki M, Pagani C, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Plotz C, Porter TA, Raino S, Rando R, Razzano M, Razzaque S, Reimer A, Reimer O, Reposeur T, Ripken J, Ritz S, Rodriguez AY, Roth M, Ryde F, Sadrozinski HFW, Sanchez D, Sander A, Scargle JD, Sgro C, Siskind EJ, Smith PD, Spandre G, Spinelli P, Starck JL, Stawarz L, 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, Vandenbroucke J, Vasileiou V, Vilchez N, Vitale V, Waite AP, Wang P, Winer BL, Wood KS, Yang Z, Ylinen T, Ziegler M (2010)

Publication Type: Journal article

Publication year: 2010

Journal

Book Volume: 719

Pages Range: 1433-1444

Journal Issue: 2

DOI: 10.1088/0004-637X/719/2/1433

Abstract

We present gamma-ray observations with the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope of the nearby radio galaxy Centaurus A (Cen A). The previous EGRET detection is confirmed, and the localization is improved using data from the first 10 months of Fermi science operation. In previous work, we presented the detection of the lobes by the LAT; in this work, we concentrate on the gamma-ray core of Cen A. Flux levels as seen by the LAT are not significantly different from that found by EGRET, nor is the extremely soft LAT spectrum (Gamma = 2.67 +/- 0.10(stat) +/- 0.08(sys) where the photon flux is Phi alpha E-Gamma). The LAT core spectrum, extrapolated to higher energies, is marginally consistent with the non-simultaneous HESS spectrum of the source. The LAT observations are complemented by simultaneous observations from Suzaku, the Swift Burst Alert Telescope and X-ray Telescope, and radio observations with the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry program, along with a variety of non-simultaneous archival data from a variety of instruments and wavelengths to produce a spectral energy distribution (SED). We fit this broadband data set with a single-zone synchrotron/synchrotron self-Compton model, which describes the radio through GeV emission well, but fails to account for the non-simultaneous higher energy TeV emission observed by HESS from 2004 to 2008. The fit requires a low Doppler factor, in contrast to BL Lac objects which generally require larger values to fit their broadband SEDs. This indicates that the gamma-ray emission originates from a slower region than that from BL Lac objects, consistent with previous modeling results from Cen A. This slower region could be a slower moving layer around a fast spine, or a slower region farther out from the black hole in a decelerating flow. The fit parameters are also consistent with Cen A being able to accelerate ultra-high energy cosmic-rays, as hinted at by results from the Auger observatory.

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) 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) Politecnico di Bari Italy (IT) École Polytechnique - Université Paris-Saclay France (FR) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) Spain (ES) National Aeronautics and Space Administration (NASA) 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 Alabama in Huntsville (UAH) United States (USA) (US) AlbaNova University Centre / Kungliga Tekniska Högskolan AlbaNova Universitetscentrum Sweden (SE) Université Toulouse III - Paul Sabatier France (FR) University of Montpellier / Université Montpellier France (FR) University of Padua / Universita degli Studi di Padova Italy (IT) United States Naval Observatory United States (USA) (US) Japan Aerospace eXploration Agency (JAXA) Japan (JP) Stockholm University / Stockholms universitet Sweden (SE) NYCB Real-Time Computing, Inc. United States (USA) (US) Università degli Studi di Perugia Italy (IT) Sonoma State University United States (USA) (US) University of Udine / Università degli Studi di Udine Italy (IT) Université Bordeaux 1, Sciences et Technologies France (FR) Pennsylvania State University (Penn State) United States (USA) (US) Hiroshima University Japan (JP) University of Maryland, Baltimore County United States (USA) (US) Institució Catalana de Recerca i Estudis Avançats (ICREA) / Catalan Institution for Research and Advanced Studies Spain (ES) Bundesamt für Kartographie und Geodäsie (BKG) / Federal Agency for Cartography and Geodesy Germany (DE) Waseda University / 早稲田大学 Japan (JP) Tokyo Institute of Technology Japan (JP) University of Denver United States (USA) (US) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics Germany (DE) University of Leicester United Kingdom (GB) University of Washington United States (USA) (US) Purdue University Northwest / Purdue University Calumet United States (USA) (US)

How to cite

APA:

Abdo, A.A., Ackermann, M., Ajello, M., Atwood, W.B., Baldini, L., Ballet, J.,... Ziegler, M. (2010). FERMI LARGE AREA TELESCOPE VIEW OF THE CORE OF THE RADIO GALAXY CENTAURUS A. Astrophysical Journal, 719(2), 1433-1444. https://doi.org/10.1088/0004-637X/719/2/1433

MLA:

Abdo, A. A., et al. "FERMI LARGE AREA TELESCOPE VIEW OF THE CORE OF THE RADIO GALAXY CENTAURUS A." Astrophysical Journal 719.2 (2010): 1433-1444.

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