SIMBAD references

We systematically analyse two GRB samples with radio-loud and radio-quiet afterglows, respectively. It is interestingly found that the radio-selected GRB samples exhibit a clear dichotomy in terms of their distributions of intrinsic durations (T_int), isotropic energies in γ-rays (E_γ, iso_), the circum-burst medium density (n), the spectral radio peak luminosity (L_ν, p_) and flux densities (F_host) of host galaxies. On average, the values of T_int, E_γ, iso_, n, L_ν, p_, and F_host of radio-quiet GRBs are relatively smaller than those of radio-loud ones. However, the redshifts and host flux densities of both samples are similarly distributed. In addition, a positive power-law correlation of L_ν,p∝E_γ, iso_^0.41±0.04^ is found for the radio-loud sample, especially in accord with the supernova-associated GRBs, which is marginally consistent with that of the radio-quiet GRB sample. A negative correlation between T_int and z is confirmed to similarly hold for both radio-loud and radio-quiet GRBs. The dividing line between short and long GRBs in the rest frame is at T_int ≃1 s. Consequently, we propose that the radio-selected GRBs could be originated from distinct progenitors and central engines, together with environments.