Observation of Very High Energy Gamma-Ray Emission from the Active Galactic Nucleus 1ES 1959+650 Using the MAGIC Telescope

Albert, J.; Aliu, E.; Anderhub, H.; Antoranz, P.; Armada, A.; Asensio, M.; Baixeras, C.; Barrio, J. A.; Bartko, H.; Bastieri, D.; Bednarek, W.; Berger, K.; Bigongiari, C.; Biland, A.; Bisesi, E.; Bock, R. K.; Bretz, T.; Britvitch, I.; Camara, M.; Chilingarian, A.; Ciprini, S.; Coarasa, J. A.; Commichau, S.; Contreras, J. L.; Cortina, J.; Danielyan, V.; Dazzi, F.; De Angelis, A.; de los Reyes, R.; De Lotto, B.; Domingo-Santamaría, E.; Dorner, D.; Doro, M.; Errando, M.; Ferenc, D.; Fernández, E.; Firpo, R.; Flix, J.; Fonseca, M. V.; Font, L.; Galante, N.; Garczarczyk, M.; Gaug, M.; Gebauer, J.; Giannitrapani, R.; Giller, M.; Goebel, F.; Hakobyan, D.; Hayashida, M.; Hengstebeck, T.; Höhne, D.; Hose, J.; Jacon, P.; Kalekin, O.; Kranich, D.; Laille, A.; Lenisa, T.; Liebing, P.; Lindfors, E.; Longo, F.; López, J.; López, M.; Lorenz, E.; Lucarelli, F.; Majumdar, P.; Maneva, G.; Mannheim, K.; Mariotti, M.; Martínez, M.; Mase, K.; Mazin, D.; Merck, C.; Merck, M.; Meucci, M.; Meyer, M.; Miranda, J. M.; Mirzoyan, R.; Mizobuchi, S.; Moralejo, A.; Nilsson, K.; Oña-Wilhelmi, E.; Orduña, R.; Otte, N.; Oya, I.; Paneque, D.; Paoletti, R.; Pasanen, M.; Pascoli, D.; Pauss, F.; Pavel, N.; Pegna, R.; Peruzzo, L.; Piccioli, A.; Pin, M.; Prandini, E.; Rico, J.; Rhode, W.; Riegel, B.; Rissi, M.; Robert, A. et al.
Bibliographical reference

The Astrophysical Journal, Volume 639, Issue 2, pp. 761-765.

Advertised on:
3
2006
Number of authors
129
IAC number of authors
0
Citations
68
Refereed citations
53
Description
The MAGIC Cerenkov telescope has observed very high energy (VHE) γ-ray emission from the active galactic nucleus 1ES 1959+650 during 6 hr in 2004 September and October. The observations were carried out alternating with observations of the Crab Nebula, whose data were used as a reference source for optimizing γ -ray/hadron separation and for flux comparison. The data analysis shows VHE γ-ray emission of 1ES 1959+650 with ~8 σ significance, at a time of low activity in both optical and X-ray wavelengths. An integral flux above ~180 GeV of about 20% that of the Crab Nebula was obtained. The light curve, sampled over 7 days, shows no significant variations. The differential energy spectrum between 180 GeV and 2 TeV can be fitted with a power-law of index -2.72+/-0.14. The spectrum is consistent with the slightly steeper spectrum seen by HEGRA at higher energies, also during periods of low X-ray activity.