Observational difference between gamma and X-ray properties of optically dark and bright GRBs

TL;DR

This study uses multivariate statistical analysis to compare gamma-ray and X-ray properties of optically dark and bright GRBs, revealing systematic differences in peak fluxes and HI column densities.

Contribution

It introduces a discriminant analysis approach to distinguish physical differences between dark and bright GRBs based on multi-wavelength data.

Findings

Optically bright GRBs have higher peak fluxes.

Optically bright GRBs have lower HI column densities.

Differences are statistically significant.

Abstract

Using the discriminant analysis of the multivariate statistical analysis we compared the distribution of the physical quantities of the optically dark and bright GRBs, detected by the BAT and XRT on board of the Swift Satellite. We found that the GRBs having detected optical transients (OT) have systematically higher peak fluxes and lower HI column densities than those without OT.