Radio-bright/dark GRBs X/radio properties

We use an updated sample of 211 GRBs and find, in agreement with previous results (although with a sample that is almost twice as large), that the intrinsic gamma-ray duration (T_int_) and isotropic equivalent energy (E_iso_) distributions between these two populations appear to be significantly different. This implies that the radio-bright GRBs are more energetic and last longer than radio-dark GRBs.

The two samples' redshift distributions (z) are not statistically different. We analyse several correlations between variables (E_iso_, T_int_, jet opening angle, and z), accounting for selection effects and redshift evolution using the Efron-Petrosian method. We find a statistically significant anticorrelation between the jet opening angle and redshift, as well as between T_int_ and redshift, for both radio-bright and radio-dark GRBs.