engleski

MAGIC observes a very high energy gamma-ray flare from 1ES0806+524

The MAGIC Collaboration reports an outburst of the Very High Energy (VHE ; >100 GeV) gamma-ray blazar 1ES0806+524. This high frequency peaked BL Lacertae object (with redshift of 0.138) was first discovered by VERITAS using 65 hours of data collected between November 2006 and April 2008 (Acciari et al. 2009, ApJL, 690, 126). No variability was found during the VERITAS observations. The MAGIC observations were triggered by an optical high-state of the source, reported by the Tuorla blazar monitoring program http://users.utu.fi/kani/1m/1ES_0806+524.html. The VHE detection is based on a 3.3 hour-long observation performed on 2011 February 24th in stereoscopic mode with the two 17m diameter imaging Cherenkov telescopes on La Palma, Canary Islands, Spain. The preliminary analysis of the MAGIC data using standard cuts yields a detection of 44 gamma-rays above 250 GeV, corresponding to a pre-trial statistical significance of 6.7 standard deviations. The observed flux is estimated to be ~5.4% of the Crab nebula flux above 250 GeV, three times higher than the previous VERITAS detection (1.8% of the Crab nebula flux). Observations on the 23rd of February did not result in a detection of the source, indicating variability on the time scale of about one day. MAGIC will continue observations of 1ES0806+524. Observations at other wavelengths are encouraged. Questions regarding the MAGIC observations should be directed to Mose Mariotti (mose.mariotti@pi.infn.it).

Optical ; >GeV ; TeV ; AGN ; Blazar

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