An observational evidence for the difference between the short and long gamma-ray bursts

The intrinsic fluence and duration distributions of gamma-ray bursts are well represented by log-normal distributions. This allows a bivariate log-normal distribution fit to be made to the BATSE short and long bursts separately. A statistically significant difference between the long and short groups is found. We argue that the effect is probably real. Applying the Cramer's theorem these results lead to some predictions for models of long and short bursts.a