Properties of gamma-ray bursts associated with supernovae and kilonovae

Abstract

ABSTRACT We systematically compare the temporal and spectral properties of 53 supernova (SN)-associated and 15 kilonova (KN)-associated gamma-ray bursts (GRBs). We find that the spectral parameters of both types of GRBs are identically and lognormally distributed, consistent with those normal GRBs. The bolometric luminosities of SN/GRBs and KN/GRBs have a triple form, with the corresponding break luminosities of SN/GRBs are roughly two orders of magnitude larger than those of KN/GRBs. We build the power-law relations between the spectral lag and the luminosity of prompt γ-rays with indices of −1.43 ± 0.33 for SN/GRBs and −2.17 ± 0.57 for KN/GRBs in the laboratory frame, which are respectively coincident with the rest-frame values. We verify that both SN/GRBs and KN/GRBs comply with their own Amati relations that match those of long and short GRBs, respectively. Analysing X-ray afterglows with good plateau segments, we build the power-law relations between the X-ray luminosity and the plateau time with an index of −1.12 ± 0.17 for KN/GRBs and −1.08 ± 0.22 for SN/GRBs, which can be well explained by the relativistic shock driven by an energy injection. The plots of luminosity-lag, Amati relation, and luminosity-time show heavy overlap between the two types of GRBs, implying that they might share the same radiation mechanism despite originating from different progenitors or central engines.