The gamma-ray burst variability-peak luminosity correlation: New results

We report test results of the correlation between the time variability and the peak luminosity of gamma-ray bursts (GRBs), using a larger sample (32) of GRBs with known redshift than that available to Reichart et al., and using as a variability measure that introduced by these authors. The results are puzzling. Assuming an isotropic-equivalent peak luminosity, as had Reichart et al., a correlation is still found, but it is less relevant and inconsistent with a power law as previously reported. Assuming as the peak luminosity that corrected for GRB beaming for a subset of 16 GRBs with known beaming angle, the correlation becomes slightly less significant.