Description
We calculate durations and spectral parameters for 207 Swift bursts detected by the Burst Alert Telescope from 2007 April to 2009 August, including 67 events with measured redshifts. This is the first supplement to our catalog of 425 Swift gamma-ray bursts (GRBs; 147 with redshifts) starting from GRB 041220. This complete and extensive data set, analyzed with a unified methodology, allows us to conduct an accurate census of intrinsic GRB energetics, hardnesses, durations, and redshifts. The GRB world model we derive reproduces well the observables from both Swift and pre-Swift satellites. Comparing to the cosmic star formation rate, we estimate that only about 0.1% of massive stars explode as bright GRBs.
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