MAGIC upper limits on the very high energy emission from gamma-ray bursts
Journal
The Astrophysical Journal 667, 358, 2007
ticlealbert2007magic, title=MAGIC upper limits on the very high energy emission from gamma-ray bursts, author=Albert, J and Aliu, E and Anderhub, H and Antoranz, P and Armada, A and Baixeras, C and Barrio, JA and Bartko, H and Bastieri, D and Becker, J an
Abstract:
The fast repositioning system of the MAGIC Telescope has allowed during its first data cycle, between 2005 and the beginning of year 2006, observing nine different GRBs as possible sources of very high energy gammas. These observations were triggered by alerts from Swift, HETE-II, and Integral; they started as fast as possible after the alerts and lasted for several minutes, with an energy threshold varying between 80 and 200 GeV, depending upon the zenith angle of the burst. No evidence for gamma signals was found, and upper limits for the flux were derived for all events, using the standard analysis chain of MAGIC. For the bursts with measured redshift, the upper limits are compatible with a power law extrapolation, when the intrinsic fluxes are evaluated taking into account the attenuation due to the scattering in the Metagalactic Radiation Field (MRF).