THE FERMI-LAT HIGH-LATITUDE SURVEY: SOURCE COUNT DISTRIBUTIONS AND THE ORIGIN OF THE EXTRAGALACTIC DIFFUSE BACKGROUND

Abdo AA, Ackermann M, Ajello M, Antolini E, 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, Bregeon J, Brez A, Brigida M, Bruel P, Burnett TH, Buson S, Caliandro GA, Cameron RA, 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, Conrad J, Costamante L, Cutini S, Dermer CD, De Angelis A, De Palma F, Do Couto E Silva E, Drell PS, Dubois R, Dumora D, Farnier C, Favuzzi C, Fegan SJ, Focke WB, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giglietto N, Giommi P, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grove JE, Guiriec S, Hadasch D, Hayashida M, Hays E, Healey SE, Horan D, Hughes RE, Itoh R, Johannesson G, Johnson AS, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kawai N, Knoedlseder J, Kuss MW, Lande J, Latronico L, Lee SH, Lemoine-Goumard M, Garde ML, Longo F, Loparco F, Lott B, Lovellette MN, Lurrano P, Madejski GM, Makeev A, 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, Ozaki M, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Porter TA, Raino S, Rando R, Razzan M, Reimer A, Reimer O, Ritz S, Rochester LS, Rodriguez AY, Romani RW, Roth M, Sadrozinski HFW, Sander A, Parkinson PMS, Scargle JD, Sgro C, Shaw MS, Smith PD, Spandre G, Spinelli P, Starck JL, Strickman MS, Strong AW, 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, 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: 720

Pages Range: 435-453

Journal Issue: 1

DOI: 10.1088/0004-637X/720/1/435

Abstract

This is the first of a series of papers aimed at characterizing the populations detected in the high-latitude sky of the Fermi-LAT survey. In this work, we focus on the intrinsic spectral and flux properties of the source sample. We show that when selection effects are properly taken into account, Fermi sources are on average steeper than previously found (e.g., in the bright source list) with an average photon index of 2.40 +/- 0.02 over the entire 0.1-100 GeV energy band. We confirm that flat spectrum radio quasars have steeper spectra than BL Lacertae objects with an average index of 2.48 +/- 0.02 versus 2.18 +/- 0.02. Using several methods, we build the deepest source count distribution at GeV energies, deriving that the intrinsic source (i.e., blazar) surface density at F-100 >= 10(-9) ph cm(2) s(-1) is 0.12(-0.02)(+0.03) deg(-2). The integration of the source count distribution yields that point sources contribute 16(+/- 1.8)% (+/- 7% systematic uncertainty) of the GeV isotropic diffuse background. At the fluxes currently reached by LAT, we can rule out the hypothesis that pointlike sources (i.e., blazars) produce a larger fraction of the diffuse emission.

Authors with CRIS profile

Involved external institutions

U.S. Naval Research Laboratory United States (USA) (US) Stanford University 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) University of Washington United States (USA) (US) Institut d'Estudis Espacials de Catalunya (IEEC) Spain (ES) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) Italy (IT) University of Padua / Universita degli Studi di Padova Italy (IT) Italian Space Agency / Agenzia Spaziale Italiana (ASI) Italy (IT) National Aeronautics and Space Administration (NASA) United States (USA) (US) Hiroshima University Japan (JP) University of Montpellier / Université Montpellier France (FR) University of California Santa Cruz United States (USA) (US) Università degli Studi di Perugia Italy (IT) Stockholm University / Stockholms universitet Sweden (SE) Centre d'Etudes Nucléaires de Bordeaux-Gradignan (CENBG) France (FR) University of Alabama in Huntsville (UAH) United States (USA) (US) Institució Catalana de Recerca i Estudis Avançats (ICREA) / Catalan Institution for Research and Advanced Studies Spain (ES) Waseda University / 早稲田大学 Japan (JP) Tokyo Institute of Technology Japan (JP) Université Toulouse III - Paul Sabatier France (FR) University of Denver United States (USA) (US) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics Germany (DE) Japan Aerospace eXploration Agency (JAXA) Japan (JP) Purdue University Northwest / Purdue University Calumet United States (USA) (US) AlbaNova University Centre / Kungliga Tekniska Högskolan AlbaNova Universitetscentrum Sweden (SE)

How to cite

APA:

Abdo, A.A., Ackermann, M., Ajello, M., Antolini, E., Baldini, L., Ballet, J.,... Ziegler, M. (2010). THE FERMI-LAT HIGH-LATITUDE SURVEY: SOURCE COUNT DISTRIBUTIONS AND THE ORIGIN OF THE EXTRAGALACTIC DIFFUSE BACKGROUND. Astrophysical Journal, 720(1), 435-453. https://dx.doi.org/10.1088/0004-637X/720/1/435

MLA:

Abdo, A. A., et al. "THE FERMI-LAT HIGH-LATITUDE SURVEY: SOURCE COUNT DISTRIBUTIONS AND THE ORIGIN OF THE EXTRAGALACTIC DIFFUSE BACKGROUND." Astrophysical Journal 720.1 (2010): 435-453.

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