Luminosities and Space Densities of Short Gamma-Ray Bursts

Abstract

Using the Euclidean value of V/V_max 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 × 10⁵¹ ergs (0.064 s)^-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 3 times lower than that of long bursts.