A search for GeV-TeV emission from Gamma-ray Bursts using the Milagro detector

The Milagro detector surveyed the sky continuously in the Very High Energy regime from January 2000 through March 2008. During that time, over 130 GRBs were detected and well localized by satellites within its 2sr field of view. We have used Milagro data to search for >1 GeV emission from these bursts. Milagro is a water Cerenkov detector designed primarily for observations in the 0.1-100 TeV energy range. In the standard mode of operation, Milagro data is used to reconstruct the direction of an incoming high energy particle by analyzing the timing information of a large number of photomultiplier tubes that are triggered in coincidence by the air shower generated when such a particle interacts with the Earth's atmosphere. Milagro data, however, can also be analyzed in "scaler mode", where the rates of individual photomultiplier tubes can be used to detect emission above 1 GeV (albeit with no directional information). Here we present results from both techniques for all known GRBs detected by BATSE, BeppoSax, HETE-2, INTEGRAL, Swift, and the IPN, within the field of view of Milagro in its 8 years of operation.