RT Journal Article T1 Detection of very high energy gamma-ray emission from the Perseus cluster head-tail galaxy IC 310 by the MAGIC telescopes A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, María Victoria A1 López Moya, Marcos A1 Miranda Pantoja, José Miguel A1 Nieto Castaño, Daniel AB We report on the detection with the MAGIC telescopes of very high energy (VHE) gamma-rays from IC 310, a head-tail radio galaxy in the Perseus galaxy cluster, observed during the interval 2008 November to 2010 February. The Fermi satellite has also detected this galaxy. The source is detected by MAGIC at a high statistical significance of 7.6 sigma in 20.6 hr of stereo data. The observed spectral energy distribution is flat with a differential spectral index of -2.00 +/- 0.14. The mean flux above 300 GeV, between 2009 October and 2010 February, (3.1 +/- 0.5) x 10(-12) cm(-2) s(-1), corresponds to (2.5 +/- 0.4)% of Crab Nebula units. Only an upper limit, of 1.9% of Crab Nebula units above 300 GeV, was obtained with the 2008 data. This, together with strong hints (>3 sigma) of flares in the middle of 2009 October and November, implies that the emission is variable. The MAGIC results favor a scenario with the VHE emission originating from the inner jet close to the central engine. More complicated models than a simple one-zone synchrotron self-Compton (SSC) scenario, e. g., multi-zone SSC, external Compton, or hadronic, may be required to explain the very flat spectrum and its extension over more than three orders of magnitude in energy. PB IOP Publishing SN 2041-8205 YR 2010 FD 2010-11-10 LK https://hdl.handle.net/20.500.14352/43911 UL https://hdl.handle.net/20.500.14352/43911 LA eng NO © The American Astronomical Society. Supported by INFN Padova.We thank the Instituto de Astrofisica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged. This work was also supported by the Marie Curie program, by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant DO02-353 of the Bulgarian NSF, by grant 127740 of the Academy of Finland, by the YIP of the Helmholtz Gemein-schaft, by the DFG Cluster of Excellence "Origin and Structure of the Universe," and by the Polish MNiSzW Grant N N203 390834. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. NO INFN Padova NO German BMBF NO Italian INFN NO Swiss National Fund SNF NO Spanish MICINN NO Marie Curie program NO Spanish Consolider-Ingenio NO Bulgarian NSF NO Academy of Finland NO YIP of the Helmholtz Gemein-schaft NO DFG NO Polish MNiSzW NO National Aeronautics and Space Administration NO MPG DS Docta Complutense RD 9 abr 2025