SIMBAD references

We analyse two distinct samples of gamma-ray bursts (GRBs), with and without radio afterglow emission. 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. Finally, in agreement with previous work, we find that very high energy (0.1-100 GeV) extended emission is present only in the radio-bright GRB sample. Our work supports the possibility that the radio-bright and radio-dark GRBs originate from different progenitors.