Bibcode
Aleksić, J.; Antonelli, L. A.; Antoranz, P.; Backes, M.; Barrio, J. A.; Bastieri, D.; Becerra-González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Borla Tridon, D.; Braun, I.; Bretz, T.; Cañellas, A.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Cossio, L.; Covino, S.; Dazzi, F.; de Angelis, A.; de Cea Del Pozo, E.; de Lotto, B.; Delgado-Méndez, C.; Diago-Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; Fruck, C.; García-López, R. J.; Garczarczyk, M.; Garrido, D.; Giavitto, G.; Godinović, N.; Hadasch, D.; Häfner, D.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Huber, B.; Jogler, T.; Klepser, S.; Krähenbühl, T.; Krause, J.; La Barbera, A.; Lelas, D.; Leonardo, E.; Lindfors, E.; Lombardi, S.; López, M.; Lorenz, E.; Majumdar, P.; Makariev, M.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Miyamoto, H.; Moldón, J.; Moralejo, A.; Nieto, D.; Nilsson, K.; Orito, R.; Oya, I.; Paoletti, R.; Pardo, S.; Paredes, J. M.; Partini, S.; Pasanen, M.; Pauss, F.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L.; Pilia, M.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E. et al.
Bibliographical reference
Astronomy and Astrophysics, Volume 530, id.A4
Advertised on:
6
2011
Journal
Citations
84
Refereed citations
62
Description
Context. 3C 279, the first quasar discovered to emit VHE γ-rays by
the MAGIC telescope in 2006, was reobserved by MAGIC in January 2007
during a major optical flare and from December 2008 to April 2009
following an alert from the Fermi space telescope on an exceptionally
high γ-ray state. Aims: The January 2007 observations
resulted in a detection on January 16 with significance 5.4σ,
corresponding to a F (>150 GeV) (3.8 ± 0.8) ×
10-11 ph cm-2 s-1 while the overall
data sample does not show significant signal. The December 2008-April
2009 observations did not detect the source. We study the
multiwavelength behaviour of the source at the epochs of MAGIC
observations, collecting quasi-simultaneous data at optical and X-ray
frequencies and for 2009 also γ-ray data from Fermi.
Methods: We study the light curves and spectral energy distribution of
the source. The spectral energy distributions of three observing epochs
(including the February 2006, which has been previously published) are
modelled with one-zone inverse Compton models and the emission on
January 16, 2007 also with two zone model and with a lepto-hadronic
model. Results: We find that the VHE γ-ray emission
detected in 2006 and 2007 challenges standard one-zone model, based on
relativistic electrons in a jet scattering broad line region photons,
while the other studied models fit the observed spectral energy
distribution more satisfactorily.