A search for GeV-TeV emission from GRBs with the Milagro detector

Abstract

Milagro is a wide field (2 sr) high duty cycle (>90%) ground-based water Cherenkov detector designed primarily for astrophysical 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. In addition, Milagro data can be analyzed in scaler mode, where the rates of individual photomultiplier tubes can be used to detect emission above ∼1GeV (albeit with no directional information). Here, we present an analysis of the Milagro data using both modes of operation, over the 1 GeV-100 TeV energy range, to search for emission from the ∼60GRBs that have occurred in the Milagro field of view in the three years since the launch of Swift. © 2008 American Institute of Physics.