Bibcode
DOI
Albert, J.; Aliu, E.; Anderhub, H.; Antonelli, L. A.; Antoranz, P.; Backes, M.; Baixeras, C.; Barrio, J. A.; Bartko, H.; Bastieri, D.; Becker, J. K.; Bednarek, W.; Berger, K.; Bernardini, E.; Bigongiari, C.; Biland, A.; Bock, R. K.; Bonnoli, G.; Bordas, P.; Bosch-Ramon, V.; Bretz, T.; Britvitch, I.; Camara, M.; Carmona, E.; Chilingarian, A.; Commichau, S.; Contreras, J. L.; Cortina, J.; Costado, M. T.; Covino, S.; Curtef, V.; Dazzi, F.; De Angelis, A.; De Cea del Pozo, E.; de los Reyes, R.; De Lotto, B.; De Maria, M.; De Sabata, F.; Delgado Mendez, C.; Dominguez, A.; Dorner, D.; Doro, M.; Errando, M.; Fagiolini, M.; Ferenc, D.; Fernández, E.; Firpo, R.; Fonseca, M. V.; Font, L.; Galante, N.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Goebel, F.; Hayashida, M.; Herrero, A.; Höhne, D.; Hose, J.; Hsu, C. C.; Huber, S.; Jogler, T.; Kranich, D.; La Barbera, A.; Laille, A.; Leonardo, E.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Lorenz, E.; Majumdar, P.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Meyer, M.; Miranda, J. M.; Mirzoyan, R.; Mizobuchi, S.; Moles, M.; Moralejo, A.; Nieto, D.; Nilsson, K.; Ninkovic, J.; Otte, N.; Oya, I.; Panniello, M.; Paoletti, R.; Paredes, J. M.; Pasanen, M.; Pascoli, D.; Pauss, F.; Pegna, R. G.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L. et al.
Bibliographical reference
The Astrophysical Journal, Volume 685, Issue 1, pp. L23-L26.
Advertised on:
9
2008
Journal
Citations
116
Refereed citations
80
Description
M87 is the only known nonblazar radio galaxy to emit very high energy
(VHE) gamma rays. During a monitoring program of M87, a rapid flare in
VHE gamma-rays was detected by the MAGIC telescope in early 2008. The
flux was found to be variable above 350 GeV on a timescale as short as 1
day at a significance level of 5.6 σ. The highest measured flux
reached 15% of the Crab Nebula flux. We observed several substantial
changes of the flux level during the 13 day observing period. The flux
at lower energies (150-350 GeV), instead, is compatible with being
constant. The energy spectrum can be described by a power law with a
photon index of 2.30 +/- 0.11stat +/- 0.20syst.
The observed day-scale flux variability at VHE prefers the M87 core as
source of the emission and implies that either the emission region is
very compact (just a few Schwarzschild radii) or the Doppler factor of
the emitting blob is rather large in the case of a nonexpanding emission
region.
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