2 BeppoSAX gamma-ray burst monitor data

The Gamma Ray Burst Monitor (GBRM), on board the BeppoSAX satellite, consists of the 4 anticoincidence CsI (Na) shields of the Phoswich Detection System (Frontera et al. 1997) with dedicated electronics and data storage. Two of the four GRBM units (1 and 3) are co-aligned with the Wide Field Cameras. The GRBM operates in the energy range 40-700 keV and the counts from each shield are used to reveal the Gamma-Ray Burst event. If the counting rate averaged on a short integration time (actually 1 s) exceeds simultaneously in two shields the background (estimated on a long integration time, actually 32 s) of $n{\sigma}$ (actually 4) then the GRBM logic is triggered and 3 different files are stored with high time resolution binning, containing the light curve from 10 s before trigger until 88 s after the trigger. In-flight data show, after proper setting of the thresholds, a stable and poissonian background, except for a few, well detected, spikes from highly charged particles (Feroci et al. 1997).