Abdo AA, Ackermann M, Ajello M, Axelsson M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Battelino M, Baughman BM, Bechtol K, Bellazzini R, Bloom ED, Bonamente E, Borgland AW, Bregeon J, Brez A, Brigida M, Bruel P, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cavazzuti E, Cecchi C, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Collmar W, Conrad J, Costamante L, Dermer CD, De Angelis A, De Palma F, Digel SW, Do Couto E Silva E, 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, Gehrels N, Germani S, Giebels B, Giglietto N, Giordano F, Giroletti M, Glanzman T, 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, Kerr M, Knoedlseder J, Kuehn F, Kuss MW, Lande J, Latronico L, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Max-Moerbeck W, Mazziotta MN, Mcconville W, Mcenery JE, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, 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, Pavlidou V, Pearson TJ, Pepe M, Pesce-Rollins M, Piron F, Porter TA, Raino S, Rando R, Razzano M, Readhead A, Reimer A, Reimer O, Reposeur T, Richards JL, Ritz S, Rodriguez AY, Romani RW, Ryde F, Sadrozinski HFW, Sambruna R, Sanchez D, Sander A, Parkinson PMS, Scargle JD, Schalk TL, Sgro C, Smith DA, Spandre G, Spinelli P, Starck JL, Stevenson M, Strickman MS, Suson DJ, Tagliaferri G, Takahashi HH, Tanaka T, Thayer JG, Thompson DJ, Tibaldo L, Tibolla O, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Vilchez N, Vitale V, Waite AP, Winer BL, Wood KS, Ylinen T, Zensus JA, Ziegler M, Ghisellini G, Maraschi L, Tavecchio F, Angelakis E (2009)

Publication Type: Journal article

Publication year: 2009


Book Volume: 699

Pages Range: 976-984

Journal Issue: 2

DOI: 10.1088/0004-637X/699/2/976


We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy. gamma-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow H beta (FWHM(H beta) similar to 1500 km s(-1)), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and gamma-ray observations are presented. Both radio and gamma-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the gamma-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and gamma-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and gamma-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti & Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

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Involved external institutions

U.S. Naval Research Laboratory US United States (USA) (US) Stanford University US United States (USA) (US) The Oskar Klein Centre SE Sweden (SE) National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) IT Italy (IT) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot FR France (FR) Ohio State University US United States (USA) (US) Politecnico di Bari IT Italy (IT) Institut national de physique nucléaire et de physique des particules (IN2P3) FR France (FR) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) ASI Science Data Center (ASDC) IT Italy (IT) National Aeronautics and Space Administration (NASA) US United States (USA) (US) University of Montpellier / Université Montpellier FR France (FR) University of Udine / Università degli Studi di Udine IT Italy (IT) Centre d'Etudes Nucléaires de Bordeaux-Gradignan (CENBG) FR France (FR) Max-Planck-Institut für Kernphysik (MPIK) / Max Planck Institute for Nuclear Physics DE Germany (DE) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics DE Germany (DE) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy DE Germany (DE) Hiroshima University / 広島大学 JP Japan (JP) University of Alabama in Huntsville (UAH) US United States (USA) (US) University of California Santa Cruz US United States (USA) (US) Waseda University / 早稲田大学 JP Japan (JP) University of Washington US United States (USA) (US) Université Toulouse III - Paul Sabatier FR France (FR) California Institute of Technology (Caltech) US United States (USA) (US) University of Denver US United States (USA) (US) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) ES Spain (ES) Purdue University Northwest / Purdue University Calumet US United States (USA) (US) Institut d'Estudis Espacials de Catalunya (IEEC) ES Spain (ES)

How to cite


Abdo, A.A., Ackermann, M., Ajello, M., Axelsson, M., Baldini, L., Ballet, J.,... Angelakis, E. (2009). FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM A RELATIVISTIC JET IN THE NARROW-LINE QUASAR PMN J0948+0022. Astrophysical Journal, 699(2), 976-984. https://doi.org/10.1088/0004-637X/699/2/976



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