IGR J17544-2619 in depth with Suzaku: direct evidence for clumpy winds in a supergiant fast X-ray transient

TL;DR

This study provides direct evidence of dense, clumpy stellar winds in a supergiant fast X-ray transient system, observed through Suzaku data revealing brief absorption enhancements during flares.

Contribution

First direct detection of clumpy stellar winds in an SFXT, using Suzaku observations to link wind structure with X-ray flare behavior.

Findings

Detected brief absorption increases during flares indicating clumpy winds.

Observed luminosity variation over a factor of 10,000.

Provided detailed insights into SFXT activity and wind properties.

Abstract

We present the first direct evidence for dense clumps of matter in the companion wind in a Supergiant Fast X-ray Transient (SFXT) binary. This is seen as a brief period of enhanced absorption during one of the bright, fast flares that distinguish these systems. The object under study was IGR J17544-2619, and a total of 236 ks of data were accumulated with the Japanese satellite Suzaku. The activity in this period spans a dynamic range of almost 10000 in luminosity and gives a detailed look at SFXT behavior.