Detection of very high energy gamma-ray emission from the gravitationally lensed blazar QSO B0218+357 with the MAGIC telescopes
: Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Arcaro, C.; Babic, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Buson, S.; Carosi, A.; Chatterjee, A.; Clavero, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Oña Wilhelmi, E.; Di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Guberman, D.; Hadasch, D.; Hahn, A.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Idec, W.; Kodani, K.; Konno, Y.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; Majumdar, P.; Makariev, M.; Mallot, K.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Moretti, E.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Nogués, L.; Paiano, S.; Palacio, J.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Toyama, T.; Treves, A.; Vanzo, G.; Verguilov, V.; Vovk, I.; Ward, J. E.; Will, M.; Wu, M. H.; Zanin, R.; Desiante, R.
Publisher: EDP Science
: 2016
: Astronomy and Astrophysics
: aap
: A98
: 595
: 11
: 1432-0746
: 1432-0746
DOI: https://doi.org/10.1051/0004-6361/201629461
: https://arxiv.org/abs/1609.01095
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 that are 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 source 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 broadband 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.
