Observation of Very High Energy γ‐Rays from the AGN 1ES 2344+514 in a Low Emission State with the MAGIC Telescope

Albert, J.; Aliu, E.; Anderhub, H.; Antoranz, P.; Armada, A.; Baixeras, C.; Barrio, J. A.; Bartko, H.; Bastieri, Denis; 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.; Ciprini, S.; 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‐santamaria, E.; Dorner, D.; Doro, Michele; Errando, M.; Fagiolini, M.; Angelis, De; Ferenc, D.; Fernandez, E.; Firpo, R.; Flix, J.; Fonseca, M. V.; Font, L.; Fuchs, M.; Galante, N.; Garcia‐lopez, R.; Garczarczyk, M.; Gaug, M.; Giller, M.; Goebel, F.; Hakobyan, D.; Hayashida, M.; Hengstebeck, T.; Herrero, A.; Hohne, D.; Hose, J.; Hsu, C. C.; Jacon, P.; Jogler, T.; Kalekin, O.; Kosyra, R.; Kranich, D.; Kritzer, R.; Laille, A.; Liebing, P.; Lindfors, E.; Lombardi, S.; Longo, F.; Lopez, J.; Lopez, M.; Lorenz, E.; Majumdar, P.; Maneva, G.; Mannheim, K.; Mansutti, O.; Mariotti, Mose'; Martinez, M.; Mazin, D.; Merck, C.; Meucci, M.; Meyer, M.; Miranda, J. M.; Mirzoyan, R.; Mizobuchi, S.; Moralejo, A.; Nilsson, K.; Ninkovic, J.; Onna‐wilhelmi, E.; Otte, N.; Oya, I.; Paneque, D.; Panniello, M.; Paoletti, R.; Paredes, J. M.; Pasanen, M.; Pascoli, Donatella; Pauss, F.; Pegna, R.; Persic, M.; Peruzzo, Luigi; Piccioli, A.; Poller, M.; Prandini, Elisa; Puchades, N.; Raymers, A.; Rhode, W.; Ribo, M.; Rico, J.; Rissi, M.; Robert, A.; Rugamer, S.; Saggion, Antonio; Sanchez, A.; Sartori, Paolo; Scalzotto, VILLI MARIO; Scapin, V.; Schmitt, R.; Schweizer, T.; Shayduk, M.; Shinozaki, K.; Shore, S. N.; Sidro, N.; Sillanpaa, A.; Sobczynska, D.; Stamerra, A.; Stark, L. S.; Takalo, L.; Temnikov, P.; Tescaro, D.; Teshima, M.; Tonello, N.; Torres, D. F.; Turini, N.; Vankov, H.; Vitale, V.; Wagner, R. M.; Wibig, T.; Wittek, W.; Zandanel, F.; Zanin, R.; Zapatero, J.

doi:10.1086/518431

The MAGIC collaboration has observed very high energy gamma-ray emission from the AGN 1ES 2344+514. A gamma-ray signal corresponding to an 11 sigma excess and an integral flux of ( 2.38 +/- 0.30(stat) +/- 0.70(syst)) x 10(-11) cm(-2) s(-1) above 200 GeV has been obtained from 23.1 hr of data taking between 2005 August 3 and 2006 January 1. The data confirm the previously detected gamma-ray emission from this object during a flare seen by the Whipple collaboration in 1995 and the evidence ( below 5 sigma significance level) from long-term observations conducted by the Whipple and HEGRA groups. The MAGIC observations show a relatively steep differential photon spectrum that can be described by a power law with a photon index of alpha = -2.95 +/- 0.12(stat) +/- 0.2(syst) between 140 GeV and 5.4 TeV. The observations reveal a low-flux state, about 6 times below the 1995 flare seen by Whipple and comparable with the previous Whipple and HEGRA long-term measurements. During the MAGIC observations no significant time variability was observed.