Luminosities and Space Densities of Short Gamma-Ray Bursts

Abstract

Using the Euclidean value of <V/Vmax> as a cosmological distance indicator, we derive the isotropic-equivalent characteristic peak luminosity of gamma-ray bursts both longer and shorter than 2 s. The short bursts have essentially the same characteristic peak luminosity of 0.6 x 10^51 erg (0.064s)^-1 as do the long bursts. This may apply also to bursts with durations less than 0.25 s. The local space density of short bursts is around three times lower than that of long bursts.