Hard X-ray bursts detected by the IBIS telescope onboard the INTEGRAL observatory in 2003–2004

All of the observations performed with the IBIS telescope onboard the INTEGRAL observatory during the first one and a half years of its in-orbit operation (from February 10, 2003, through July 2, 2004) have been analyzed to find X-ray bursts. The time history of the IBIS/ISGRI total count rate in the energy range 15–25 keV revealed 1077 bursts of durations from ∼5 to ∼500 s with a high statistical significance (over the entire period of observations, only one event could be detected by chance with a probability of 20%). A part from the events associated with cosmic gamma-ray bursts (detected in the field of view or passed through the IBIS shield), solar flares, and activity of the soft gamma repeater SGR 1806-20, we were able to localize 105 bursts and, with one exception, to identify them with previously known persistent or transient X-ray sources (96 were identified with known X-ray bursters). In one case, the burst source was a new burster in a low state that received the name IGR J17364-2711. Basic parameters of the localized bursts and their identifications are presented in the catalog of bursts. Curiously enough, 61 bursts were detected from one X-ray burster, GX 354-0. The statistical distributions of bursts in duration, maximum flux, and recurrence time have been analyzed for this source. Some of the bursts observed with the IBIS/ISGRI telescope were also detected by the JEM-X telescope onboard the INTEGRAL observatory in the standard X-ray energy range 3–20 keV.