First INTEGRAL SPI-ACS Gamma-Ray Burst Catalogue

SPI-ACS works as a nearly omnidirectional gamma-ray burst detector above ~80keV but lacks spatial and spectral information. In this catalogue, the properties derived from the 50ms light curves (e.g., T_90_, C_max_, C_int_, variability, V/V_max_) are given for each candidate burst in the sample.

A strong excess of very short events with durations <0.25s is found. This population is shown to be significantly different from the short- and long-duration burst sample by means of the intensity distribution and V/V_max_ test and is certainly connected with cosmic ray hits in the detector. A rate of 0.3 true gamma-ray bursts per day is observed.