Bibcode
Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; de Almeida, U. Barres; Barrio, J. A.; Becerra-González, J.; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Fidalgo, D. Carreto; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Mendez, C. Delgado; Doert, M.; Domínguez, A.; Prester, D. Dominis; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García-López, R. J.; Garczarczyk, M.; Terrats, D. Garrido; Gaug, M.; Giavitto, G.; Godinović, N.; Muñoz, A. González; Gozzini, S. R.; Hadasch, D.; Hayashida, M.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; Barbera, A. La; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K. et al.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 440, Issue 1, p.530-535
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3
2014
Citations
2
Refereed citations
1
Description
The bright gamma-ray quasar 4C +55.17 is a distant source (z = 0.896)
with a hard spectrum at GeV energies as observed by the Large Area
Telescope (LAT) on board the Fermi satellite. This source is identified
as a good source candidate for very high energy (VHE; >30 GeV)
gamma-rays. In general, VHE gamma-rays from distant sources provide a
unique opportunity to study the extragalactic background light (EBL) and
underlying astrophysics. The flux intensity of this source in the VHE
range is investigated. Then, constraints on the EBL are derived from the
attenuation of gamma-ray photons coming from the distant blazar. We
searched for a gamma-ray signal from this object using the 35 h
observations taken by the MAGIC (Major Atmospheric Gamma-ray Imaging
Cherenkov) telescopes between 2010 November and 2011 January. No
significant VHE gamma-ray signal was detected. We computed the upper
limits of the integrated gamma-ray flux at the 95 per cent confidence
level of 9.4 × 10-12 and 2.5 × 10-12
cm-2 s-1 above 100 and 200 GeV, respectively. The
differential upper limits in four energy bins in the range from 80 to
500 GeV are also derived. The upper limits are consistent with the
attenuation predicted by low-flux EBL models on the assumption of a
simple power-law spectrum extrapolated from LAT data.
Related projects
Particle Astrophysics
The MAGIC Collaboration is integrated by 20 research institutes and university departments from Armenia, Bulgaria, Finland, Germany, Italy, Poland, Spain, Switzerland and USA. The collaboration comprises two 17m diameter telescopes, located at the Roque de los Muchachos Observatory, designed to measure the Cherenkov radiation associated with
Ramón
García López