MAGIC Gamma-ray Telescope Observation of the Perseus Cluster of Galaxies: implications for cosmic rays, dark matter, and NGC1275
Creators: name: The MAGIC Collaboration
name: Aleksić, J.
name: Antonelli, L. A.
name: Antoranz, P.
name: Backes, M.
name: Baixeras, C.
name: Balestra, S.
name: Barrio, J. A.
name: Bastieri, D.
name: González, J. Becerra
name: Bednarek, W.
name: Berdyugin, A.
name: Berger, K.
name: Bernardini, E.
name: Biland, A.
name: Bock, R. K.
name: Bonnoli, G.
name: Bordas, P.
name: Tridon, D. Borla
name: Bosch-Ramon, V.
name: Bose, D.
name: Braun, I.
name: Bretz, T.
name: Britzger, D.
name: Camara, M.
name: Carmona, E.
name: Carosi, A.
name: Colin, P.
name: Commichau, S.
name: Contreras, J. L.
name: Cortina, J.
name: Costado, M. T.
name: Covino, S.
name: Dazzi, F.
name: De Angelis, A.
name: del Pozo, E. De Cea
name: Reyes, R. De los
name: De Lotto, B.
name: De Maria, M.
name: De Sabata, F.
name: Mendez, C. Delgado
name: Doert, M.
name: Domínguez, A.
name: Prester, D. Dominis
name: Dorner, D.
name: Doro, M.
name: Elsaesser, D.
name: Errando, M.
name: Ferenc, D.
name: Fonseca, M. V.
name: Font, L.
name: Galante, N.
name: López, R. J. García
name: Garczarczyk, M.
name: Gaug, M.
name: Godinovic, N.
name: Hadasch, D.
name: Herrero, A.
name: Hildebrand, D.
name: Höhne-Mönch, D.
name: Hose, J.
name: Hrupec, D.
name: Hsu, C. C.
name: Jogler, T.
name: Klepser, S.
name: Krähenbühl, T.
name: Kranich, D.
name: La Barbera, A.
name: Laille, A.
name: Leonardo, E.
name: Lindfors, E.
name: Lombardi, S.
name: Longo, F.
name: López, M.
name: Lorenz, E.
name: Majumdar, P.
name: Maneva, G.
name: Mankuzhiyil, N.
name: Mannheim, K.
name: Maraschi, L.
name: Mariotti, M.
name: Martínez, M.
name: Mazin, D.
name: Meucci, M.
name: Miranda, J. M.
name: Mirzoyan, R.
name: Miyamoto, H.
name: Moldón, J.
name: Moles, M.
name: Moralejo, A.
name: Nieto, D.
name: Nilsson, K.
name: Ninkovic, J.
name: Orito, R.
name: Oya, I.
name: Paiano, S.
name: Paoletti, R.
name: Paredes, J. M.
name: Partini, S.
name: Pasanen, M.
name: Pascoli, D.
name: Pauss, F.
name: Pegna, R. G.
name: Perez-Torres, M. A.
name: Persic, M.
name: Peruzzo, L.
name: Prada, F.
name: Prandini, E.
name: Puchades, N.
name: Puljak, I.
name: Reichardt, I.
name: Rhode, W.
name: Ribó, M.
name: Rico, J.
name: Rissi, M.
name: Rügamer, S.
name: Saggion, A.
name: Saito, T. Y.
name: Salvati, M.
name: Sánchez-Conde, M.
name: Satalecka, K.
name: Scalzotto, V.
name: Scapin, V.
name: Schultz, C.
name: Schweizer, T.
name: Shayduk, M.
name: Shore, S. N.
name: Sierpowska-Bartosik, A.
name: Sillanpää, A.
name: Sitarek, J.
name: Sobczynska, D.
name: Spanier, F.
name: Spiro, S.
name: Stamerra, A.
name: Steinke, B.
name: Struebig, J. C.
name: Suric, T.
name: Takalo, L.
name: Tavecchio, F.
name: Temnikov, P.
name: Terzic, T.
name: Tescaro, D.
name: Teshima, M.
name: Torres, D. F.
name: Vankov, H.
name: Wagner, R. M.
name: Zabalza, V.
name: Zandanel, F.
name: Zanin, R.
name: Zapatero, J.
name: Pfrommer, C.
name: Pinzke, A.
name: Enßlin, T. A.
name: Inoue, S.
name: Ghisellini, G.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hr during 2008 November and December. The resulting upper limits on the gamma-ray emission above 100 GeV are in the range of 4.6 to 7.5 x 10^{-12} cm^{-2} s^{-1} for spectral indices from -1.5 to -2.5, thereby constraining the emission produced by cosmic rays, dark matter annihilations, and the central radio galaxy NGC1275. Results are compatible with cosmological cluster simulations for the cosmic-ray-induced gamma-ray emission, constraining the average cosmic ray-to-thermal pressure to &lt;4% for the cluster core region (&lt;8% for the entire cluster). Using simplified assumptions adopted in earlier work (a power-law spectrum with an index of -2.1, constant cosmic ray-to-thermal pressure for the peripheral cluster regions while accounting for the adiabatic contraction during the cooling flow formation), we would limit the ratio of cosmic ray-to-thermal energy to E_CR/E_th&lt;3%. The upper limit also translates into a level of gamma-ray emission from possible annihilations of the cluster dark matter (the dominant mass component) that is consistent with boost factors of ~10^4 for the typically expected dark matter annihilation-induced emission. Finally, the upper limits obtained for the gamma-ray emission of the central radio galaxy NGC1275 are consistent with the recent detection by the Fermi-LAT satellite. Due to the extremely large Doppler factors required for the jet, a one-zone synchrotron self-Compton model is implausible in this case. We reproduce the observed spectral energy density by using the structured jet (spine-layer) model which has previously been adopted to explain the high-energy emission of radio galaxies.
description: 15 pages, 5 figures; accepted for publication in ApJ; updated to match the journal final version