The Emission Time of Gamma‐Ray Bursts

Abstract

The concept of emission time τN is suggested as a temporal parameter which is complementary to the classical parameters of duration times T50 and T90. The emission time is defined as the time of emission of N% of the total fluence. The definition adds the time bins of high fluence in decreasing fluence rank until N% of the fluence has been reached. The emission time interval excludes low-emission intervals of bursts, and so the emission time characterizes the state of high-power emission. The distribution of this new parameter is found to be bimodal for bright bursts. The distributions of emission time τ30 and τ50, for groups based on burst intensity, are also compared.