Diagnosing the burst influence upon accretion in the clocked burster GS 1826--238

TL;DR

This study analyzes 68 X-ray bursts from GS 1826--238 to understand how burst emission affects accretion processes, revealing complex interactions involving coronal cooling and potential impacts on corona formation.

Contribution

It provides a joint analysis of soft and hard X-ray responses to bursts, introducing a model with variable parameters to describe the influence on accretion in neutron star systems.

Findings

Burst influence can be modeled with the CompTT model with variable parameters.

Burst emission impacts coronal cooling, possibly affecting corona formation.

Observations suggest additional mechanisms beyond simple cooling are involved.

Abstract

Type-I X-ray bursts on the surface of a neutron star are a unique probe to the accretion in X-ray binary systems. However, we know little about the feedback of the burst emission upon accretion. Hard X-ray shortages and enhancements of the persistent emission at soft X-rays have been observed. To put these findings in context with the aim of understanding the possible mechanism underneath, we investigated 68 bursts seen by RXTE from the clocked burster GS 1826--238. We diagnosed jointly the burst influence at both soft and hard X-rays, and found that the observations can be described as the CompTT model with variable normalization, electron temperature and optical depth. Putting these results in a scenario of coronal Compton cooling via the burst emission would lead to a shortage of the cooling power, which may suggest that additional consideration like the influence of the burst on the corona formation should be accounted for as well.