Observation of GRBs with AGILE

Since its early phases of operation, the AGILE satellite is observing Gamma Ray Bursts (GRBs) over an energy range potentially spanning six orders of magnitude. In the hard X-ray band the SuperAGILE imager provides localization of about one GRB/month plus the detection of 1–2 GRBs per month out of its field of view. The MiniCalorimeter detects about one GRB/week in the 350 keV–100 MeV energy range, plus several other transients at very short time scales. In fact, the onboard MCAL trigger logic, implemented for the first time on time windows as short as 300 microseconds, is particularly suitable for very short bursts detection. The Gamma-Ray Imaging Detector (GRID), sensitive in the 30 MeV–30 GeV range, firmly detected three GRBs (GRB 080514B, GRB 090401B and GRB 090510) plus some other candidates at a lower significance level. Moreover, all GRBs localized by other spacecrafts inside the GRID field of view are currently searched for possible detection, and upper limits are provided. In this paper we review the status of the observation of GRBs with AGILE, with particular emphasis on high energy and short time scales detections.