Detection of very high energy gamma-ray emission from the gravitationally-lensed blazar QSO B0218+357 with the MAGIC telescopes
Creators: name: MAGIC Collaboration
name: Ahnen, M. L.
name: Ansoldi, S.
name: Antonelli, L. A.
name: Antoranz, P.
name: Arcaro, C.
name: Babic, A.
name: Banerjee, B.
name: Bangale, P.
name: de Almeida, U. Barres
name: Barrio, J. A.
name: González, J. Becerra
name: Bednarek, W.
name: Bernardini, E.
name: Berti, A.
name: Biasuzzi, B.
name: Biland, A.
name: Blanch, O.
name: Bonnefoy, S.
name: Bonnoli, G.
name: Borracci, F.
name: Bretz, T.
name: Buson, S.
name: Carosi, A.
name: Chatterjee, A.
name: Clavero, R.
name: Colin, P.
name: Colombo, E.
name: Contreras, J. L.
name: Cortina, J.
name: Covino, S.
name: Da Vela, P.
name: Dazzi, F.
name: De Angelis, A.
name: De Lotto, B.
name: Wilhelmi, E. de Oña
name: Di Pierro, F.
name: Doert, M.
name: Domínguez, A.
name: Prester, D. Dominis
name: Dorner, D.
name: Doro, M.
name: Einecke, S.
name: Glawion, D. Eisenacher
name: Elsaesser, D.
name: Engelkemeier, M.
name: Ramazani, V. Fallah
name: Fernández-Barral, A.
name: Fidalgo, D.
name: Fonseca, M. V.
name: Font, L.
name: Frantzen, K.
name: Fruck, C.
name: Galindo, D.
name: López, R. J. García
name: Garczarczyk, M.
name: Terrats, D. Garrido
name: Gaug, M.
name: Giammaria, P.
name: Godinović, N.
name: Gora, D.
name: Guberman, D.
name: Hadasch, D.
name: Hahn, A.
name: Hayashida, M.
name: Herrera, J.
name: Hose, J.
name: Hrupec, D.
name: Hughes, G.
name: Idec, W.
name: Kodani, K.
name: Konno, Y.
name: Kubo, H.
name: Kushida, J.
name: La Barbera, A.
name: Lelas, D.
name: Lindfors, E.
name: Lombardi, S.
name: Longo, F.
name: López, M.
name: López-Coto, R.
name: Majumdar, P.
name: Makariev, M.
name: Mallot, K.
name: Maneva, G.
name: Manganaro, M.
name: Mannheim, K.
name: Maraschi, L.
name: Marcote, B.
name: Mariotti, M.
name: Martínez, M.
name: Mazin, D.
name: Menzel, U.
name: Miranda, J. M.
name: Mirzoyan, R.
name: Moralejo, A.
name: Moretti, E.
name: Nakajima, D.
name: Neustroev, V.
name: Niedzwiecki, A.
name: Rosillo, M. Nievas
name: Nilsson, K.
name: Nishijima, K.
name: Noda, K.
name: Nogués, L.
name: Paiano, S.
name: Palacio, J.
name: Palatiello, M.
name: Paneque, D.
name: Paoletti, R.
name: Paredes, J. M.
name: Paredes-Fortuny, X.
name: Pedaletti, G.
name: Peresano, M.
name: Perri, L.
name: Persic, M.
name: Poutanen, J.
name: Moroni, P. G. Prada
name: Prandini, E.
name: Puljak, I.
name: Garcia, J. R.
name: Reichardt, I.
name: Rhode, W.
name: Ribó, M.
name: Rico, J.
name: Saito, T.
name: Satalecka, K.
name: Schroeder, S.
name: Schweizer, T.
name: Shore, S. N.
name: Sillanpää, A.
name: Sitarek, J.
name: Snidaric, I.
name: Sobczynska, D.
name: Stamerra, A.
name: Strzys, M.
name: Surić, T.
name: Takalo, L.
name: Tavecchio, F.
name: Temnikov, P.
name: Terzić, T.
name: Tescaro, D.
name: Teshima, M.
name: Torres, D. F.
name: Toyama, T.
name: Treves, A.
name: Vanzo, G.
name: Verguilov, V.
name: Vovk, I.
name: Ward, J. E.
name: Will, M.
name: Wu, M. H.
name: Zanin, R.
name: Desiante, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Context. QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components, spatially indistinguishable by gamma-ray instruments, but separated by a 10-12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes. Aims. The spectral energy distribution of QSO B0218+357 can give information on the energetics of z ~ 1 very high energy gamma- ray sources. Moreover the gamma-ray emission can also be used as a probe of the extragalactic background light at z ~ 1. Methods. MAGIC performed observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data, obtained by Fermi-LAT and MAGIC, are used to set constraints on the extragalactic background light. Results. Very high energy gamma-ray emission was detected from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray sources detected to date. The observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broad band emission can be modeled in the framework of a two zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region.
description: 11 pages, 6 figures, accepted for publication in A&amp;A