SEARCH FOR COSMIC-RAY-INDUCED GAMMA-RAY EMISSION IN GALAXY CLUSTERS

Ackermann M, Ajello M, Albert A, Allafort A, Atwood WB, Baldini L, Ballet J, Barbiellini G, Bastieri D, Bechtol K, Bellazzini R, Bloom ED, Bonamente E, Bottacini E, Brandt TJ, Bregeon J, Brigida M, Bruel P, Buehler R, Buson S, Caliandro GA, Cameron RA, Caraveo PA, Cavazzuti E, Chaves RCG, Chiang J, Chiaro G, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, D'Ammando F, de Angelis A, de Palma F, Dermer CD, Digel SW, Drell PS, Drlica-Wagner A, Favuzzi C, Franckowiak A, Funk S, Fusco P, Gargano F, Gasparrini D, Germani S, Giglietto N, Giordano F, Giroletti M, Godfrey G, Gomez-Vargas GA, Grenier IA, Guiriec S, Gustafsson M, Hadasch D, Hayashida M, Hewitt J, Hughes RE, Jeltema TE, Johannesson G, Johnson AS, Kamae T, Kataoka J, Knoedlseder J, Kuss M, Lande J, Larsson S, Latronico L, Garde ML, Longo F, Loparco F, Lovellette MN, Lubrano P, Mayer M, Mazziotta MN, McEnery JE, Michelson PF, Mitthumsiri W, Mizuno T, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nemmen R, Nuss E, Ohsugi T, Orienti M, Orlando E, Ormes JF, Perkins JS, Pesce-Rollins M, Piron F, Pivato G, Raino S, Rando R, Razzano M, Razzaque S, Reimer A, Reimer O, Ruan J, Sanchez-Conde M, Schulz A, Sgro C, Siskind EJ, Spandre G, Spinelli P, Storm E, Strong AW, Suson DJ, Takahashi H, Thayer JG, Thayer JB, Thompson DJ, Tibaldo L, Tinivella M, Torres DF, Troja E, Uchiyama Y, Usher TL, Vandenbroucke J, Vianello G, Vitale V, Winer BL, Wood KS, Zimmer S, Pinzke A, Pfrommer C (2014)


Publication Status: Published

Publication Type: Journal article

Publication year: 2014

Journal

Publisher: American Astronomical Society

Book Volume: 787

DOI: 10.1088/0004-637X/787/1/18

Abstract

Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into gamma rays that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended gamma-ray emission at the locations of 50 galaxy clusters in four years of Fermi-LAT data under the assumption of the universal cosmic-ray (CR) model proposed by Pinzke & Pfrommer. We find an excess at a significance of 2.7 sigma, which upon closer inspection, however, is correlated to individual excess emission toward three galaxy clusters: A400, A1367, and A3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background systems (for example, radio galaxies within the clusters). Through the combined analysis of 50 clusters, we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the CR to thermal pressure ratio within the virial radius, R-200, to be below 1.25%-1.4% depending on the morphological classification. In addition, we derive new limits on the gamma-ray flux from individual clusters in our sample.

Authors with CRIS profile

Involved external institutions

Deutsches Elektronen-Synchrotron DESY DE Germany (DE) University of California US United States (USA) (US) Heidelberg Institute for Theoretical Studies GmbH (HITS) DE Germany (DE) Ohio State University US United States (USA) (US) University of California Santa Cruz US United States (USA) (US) University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro IT Italy (IT) University of Udine / Università degli Studi di Udine IT Italy (IT) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot FR France (FR) National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) IT Italy (IT) Université libre de Bruxelles (ULB) / Free University of Brussels BE Belgium (BE) Stanford University US United States (USA) (US) Italian Space Agency / Agenzia Spaziale Italiana (ASI) IT Italy (IT) Stockholm University / Stockholms universitet SE Sweden (SE) University of Johannesburg ZA South Africa (ZA) Hiroshima University JP Japan (JP) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics DE Germany (DE) Washington University US United States (USA) (US) University of Padua / Universita degli Studi di Padova IT Italy (IT) National Aeronautics and Space Administration (NASA) US United States (USA) (US) National Center for Scientific Research / Centre national de la recherche scientifique (CNRS) FR France (FR) Waseda University / 早稲田大学 JP Japan (JP) Institut de Ciències de l'Espai (ICE) ES Spain (ES) U.S. Naval Research Laboratory US United States (USA) (US) NYCB Real-Time Computing, Inc. US United States (USA) (US) University of Pisa / Università di Pisa (UniPi) IT Italy (IT) University of California, Berkeley US United States (USA) (US) University of Iceland (UI) / Háskóli Íslands IS Iceland (IS) University of Montpellier / Université Montpellier FR France (FR) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) École Polytechnique - Université Paris-Saclay FR France (FR) University of Denver US United States (USA) (US) Purdue University Northwest / Purdue University Calumet US United States (USA) (US)

How to cite

APA:

Ackermann, M., Ajello, M., Albert, A., Allafort, A., Atwood, W.B., Baldini, L.,... Pfrommer, C. (2014). SEARCH FOR COSMIC-RAY-INDUCED GAMMA-RAY EMISSION IN GALAXY CLUSTERS. Astrophysical Journal, 787. https://dx.doi.org/10.1088/0004-637X/787/1/18

MLA:

Ackermann, M., et al. "SEARCH FOR COSMIC-RAY-INDUCED GAMMA-RAY EMISSION IN GALAXY CLUSTERS." Astrophysical Journal 787 (2014).

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