BAT2 GRB Catalog—Prompt Emission Properties of Swift GRBs—

We present the second Swift Burst Alert Telescope (BAT) catalog of gamma‐ray bursts (GRBs), which contains 476 bursts detected by the BAT between 2004 December 19 and 2009 December 21. This catalog presents burst trigger time, location, 90% error radius, duration, fluence, peak flux, time‐averaged spectral parameters and time‐resolved spectral parameters measured by the BAT. The BAT $T90$ duration peaks at 70 s. We confirm that the spectra of the BAT short‐duration GRBs are generally harder than those of the long‐duration GRBs. The observed durations of the BAT high redshift GRBs are not systematically longer than those of the moderate redshift GRBs. Furthermore, the observed spectra of the BAT high redshift GRBs are similar to or harder than the moderate redshift GRBs.