Ackermann M, Ajello M, Allafort A, Baldini L, Ballet J, Barbiellini G, Bastieri D, Bechtol K, Bellazzini R, Blandford RD, Blasi P, Bloom ED, Bonamente E, Borgland AW, Bouvier A, Brandt TJ, Bregeon J, Brigida M, Bruel P, Buehler R, 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, Colafrancesco S, Cominsky LR, Conrad J, Dermer CD, De Palma F, Silva EDCE, Drell PS, Dubois R, Dumora D, Edmonds Y, Farnier C, Favuzzi C, Frailis M, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giglietto N, Giordano F, Giroletti M, Glanzman T, Godfrey G, Grenier IA, Grondin MH, Guiriec S, Hadasch D, Harding AK, Hayashida M, Hays E, Horan D, Hughes RE, Jeltema TE, Johannesson G, Johnson AS, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kerr M, Knoedlseder J, Kuss MW, Lande J, Latronico L, Lee SH, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Mazziotta MN, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Naumann-Godo M, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes JF, Ozaki M, Paneque D, Panetta JH, Pepe M, Pesce-Rollins M, Petrosian V, Pfrommer C, Piron F, Porter TA, Profumo S, Raino S, Rando R, Razzano M, Reimer A, Reimer O, Reposeur T, Ripken J, Ritz S, Rodriguez AY, Romani RW, Roth M, Sadrozinski HFW, Sander A, Parkinson PMS, Scargle JD, Sgro C, Siskind EJ, Smith PD, Spandre G, Spinelli P, Starck JL, Stawarz L, Strickman MS, Strong AW, Suson DJ, Tajima H, Takahashi HH, Takahashi T, Tanaka T, Thayer JB, Thayer JG, Tibaldo L, Tibolla O, 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
Book Volume: 717
Pages Range: L71-L78
Journal Issue: 1
DOI: 10.1088/2041-8205/717/1/L71
The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium (ICM). Those electrons and positrons are either injected into and accelerated directly in the ICM, or produced as secondary pairs by cosmic-ray ions scattering on ambient protons. Radiation mechanisms involving the energetic leptons together with the decay of neutral pions produced by hadronic interactions have the potential to produce abundant GeV photons. Here, we report on the search for GeV emission from clusters of galaxies using data collected by the Large Area Telescope on the Fermi Gamma-ray Space Telescope from 2008 August to 2010 February. Thirty-three galaxy clusters have been selected according to their proximity and high mass, X-ray flux and temperature, and indications of non-thermal activity for this study. We report upper limits on the photon flux in the range 0.2-100 GeV toward a sample of observed clusters (typical values (1-5) x 10(-9) photon cm(-2) s(-1)) considering both point-like and spatially resolved models for the high-energy emission and discuss how these results constrain the characteristics of energetic leptons and hadrons, and magnetic fields in the ICM. The volume-averaged relativistic-hadron-to-thermal energy density ratio is found to be <5%-10% in several clusters.
APA:
Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G.,... Ziegler, M. (2010). GeV GAMMA-RAY FLUX UPPER LIMITS FROM CLUSTERS OF GALAXIES. Astrophysical Journal Letters, 717(1), L71-L78. https://doi.org/10.1088/2041-8205/717/1/L71
MLA:
Ackermann, Markus, et al. "GeV GAMMA-RAY FLUX UPPER LIMITS FROM CLUSTERS OF GALAXIES." Astrophysical Journal Letters 717.1 (2010): L71-L78.
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