Bibcode
DOI
Albert, J.; Aliu, E.; Anderhub, H.; Antoranz, P.; Armada, A.; Baixeras, C.; Barrio, J. A.; Bartko, H.; Bastieri, D.; Becker, J. K.; Bednarek, W.; Berger, K.; Bigongiari, C.; Biland, A.; Bock, R. K.; Bordas, P.; Bosch-Ramon, V.; Bretz, T.; Britvitch, I.; Camara, M.; Carmona, E.; Chilingarian, A.; Coarasa, J. A.; Commichau, S.; Contreras, J. L.; Cortina, J.; Costado, M. T.; Curtef, V.; Danielyan, V.; Dazzi, F.; De Angelis, A.; Delgado, C.; de los Reyes, R.; De Lotto, B.; Domingo-Santamaría, E.; Dorner, D.; Doro, M.; Errando, M.; Fagiolini, M.; Ferenc, D.; Fernández, E.; Firpo, R.; Flix, J.; Fonseca, M. V.; Font, L.; Fuchs, M.; Galante, N.; García-López, R.; Garczarczyk, M.; Gaug, M.; Giller, M.; Goebel, F.; Hakobyan, D.; Hayashida, M.; Hengstebeck, T.; Herrero, A.; Höhne, D.; Hose, J.; Hsu, C. C.; Jacon, P.; Jogler, T.; Kosyra, R.; Kranich, D.; Kritzer, R.; Laille, A.; Lindfors, E.; Lombardi, S.; Longo, F.; López, J.; López, M.; Lorenz, E.; Majumdar, P.; Maneva, G.; Mannheim, K.; Mansutti, O.; Mariotti, M.; Martínez, M.; Mazin, D.; Merck, C.; Meucci, M.; Meyer, M.; Miranda, J. M.; Mirzoyan, R.; Mizobuchi, S.; Moralejo, A.; Nilsson, K.; Ninkovic, J.; Oña-Wilhelmi, E.; Otte, N.; Oya, I.; Paneque, D.; Panniello, M.; Paoletti, R.; Paredes, J. M.; Pasanen, M.; Pascoli, D.; Pauss, F.; Pegna, R.; Persic, M.; Peruzzo, L. et al.
Bibliographical reference
The Astrophysical Journal, Volume 666, Issue 1, pp. L17-L20.
Advertised on:
9
2007
Journal
Citations
134
Refereed citations
107
Description
The MAGIC collaboration observed BL Lacertae for 22.2 hr during 2005
August to December and for 26 hr during 2006 July to September. The
source is the historical prototype and eponym of a class of
low-frequency-peaked BL Lacertae (LBL) objects. A very high energy (VHE)
γ-ray signal was discovered with a 5.1 σ excess in the 2005
data. Above 200 GeV, an integral flux of
(0.6+/-0.2)×10-11 cm-2 s-1 was
measured, corresponding to approximately 3% of the Crab flux. The
differential spectrum between 150 and 900 GeV is rather steep with a
photon index of -3.6 +/- 0.5. The light curve shows no significant
variability during the observations in 2005. For the first time a clear
detection of VHE γ-ray emission from an LBL object was obtained
with a signal below previous upper limits. The 2006 data show no
significant excess. This drop in flux follows the observed trend in
optical activity.