Bibcode
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. et al.
Bibliographical reference
Astronomy and Astrophysics, Volume 595, id.A98, 11 pp.
Advertised on:
11
2016
Journal
Citations
60
Refereed citations
46
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 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.