Author/Authors :
Mirabel، I. F. نويسنده , , Hjorth، J. نويسنده , , Fruchter، A. S. نويسنده , , Gorosabel، J. نويسنده , , Pian، E. نويسنده , , Ubertini، P. نويسنده , , Gotz، D. نويسنده , , Mereghetti، S. نويسنده , , Hurley، K. نويسنده , , Deluit، S. نويسنده , , Feroci، M. نويسنده , , Frontera، F. نويسنده , , Hartmann، D. H. نويسنده , , Hudec، R. نويسنده , , Pizzichini، G. نويسنده , , Winkler، C. نويسنده ,
Abstract :
A long Gamma-Ray Burst (GRB) was detected with the instruments on board the INTEGRAL satellite on January 31 2003. Although most of the GRB, which lasted ~150 s, occurred during a satellite slew, the automatic software of the INTEGRAL Burst Alert System was able to detect it in near-real time. Here we report the results obtained with the IBIS instrument, which detected GRB 030131 in the 15 keV-200 keV energy range, and ESO/VLT observations of its optical transient. The burst displays a complex time profile with numerous peaks. The peak spectrum can be described by a single power law with photon index (gamma)=~ 1.7 and has a flux of ~2 photons cm^ -2 s^ -1 in the 20-200 keV energy band. The high sensitivity of IBIS has made it possible for the first time to perform detailed time-resolved spectroscopy of a GRB with a fluence of 7*10 ^-6 erg cm^ -2 (20-200 keV).
