Determining the Gamma-Ray Burst Rate as a Function of Redshift

Abstract

We exploit the 14 gamma-ray bursts (GRBs) with known redshifts z and the 7 GRBs for which there are constraints on z to determine the GRB rate R_{GRB}(z), using a method based on Bayesian inference. We find that, despite the qualitative differences between the observed GRB rate and estimates of the SFR in the universe, current data are consistent with R_{GRB}(z) being proportional to the SFR.Comment: To appear in Procs. of Gamma-Ray Bursts in the Afterglow Era: 2nd Workshop, 3 pages, 3 figures, LaTe