Revisiting the characteristics of the spectral lags in short gamma-ray bursts

Abstract

In this paper, we restudy the spectral lag features of short bright gamma-ray bursts (T90 < 2.6s) with a BATSE time-tagged event (TTE) sample including 65 single pulse bursts. We also make an investigation on the characteristics of ratios between the spectral lag and the full width at half maximum ($FWHM$) of the pulses, called relative spectral lags (RSLs). We draw the conclusions as follows: 1) Spectral lags of short GRBs are normally distributed and concentrated on around the value of 0.014 with 40 percent of them having negative lags. With K-S test, we find the lag distribution is identical with a normal one caused by white noises, which indicates the lags of the vast majority of short bursts are so small that they are negligible as Norris et al. have suggested.