Studying the variability of the X-ray spectral parameters of high-redshift GRBs' afterglows

TL;DR

This study investigates the variability of X-ray spectral parameters, especially hydrogen column density, in high-redshift GRB afterglows using Swift data, finding no significant variability in N(H).

Contribution

It assesses the robustness of spectral fittings and the sensitivity to initial parameters in high-redshift GRB X-ray data.

Findings

No significant variability in N(H) during GRB outbursts

Examined the robustness of spectral fitting methods

Analyzed the sensitivity of spectral parameters to initial conditions

Abstract

The Swift satellite has observed more than a thousand GRBs with X-ray data. Almost a third of them have redshift measurement, too. Here we start to investigate the X-ray spectral fitting of the data considering the low energy part where the N(H) absorption happens. Based on the available more accurate input data we examined the robustness of previous fittings and tested how sensitive the changes of the starting parameters are. We studied the change of the intrinsic hydrogen column density during the outburst for a few events. No significant variability of N(H) column density was identified.