Statistical classification of gamma-ray bursts based on the Amati relation

Understand

Gamma-ray bursts (GRBs) are believed to belong to two classes and they are conventionally divided according to their durations.

• This classification scheme is not satisfied due to the fact that duration distributions of the two classes are heavily overlapped.
• We collect a new sample (153 sources) of GRBs and investigate the distribution of the logarithmic deviation of the $E_p$ value from the Amati relation.
• The distribution possesses an obvious bimodality structure and it can be accounted for by the combination of two Gaussian curves.