Swift/XRT monitoring of the Supergiant Fast X-ray Transient IGR J18483-0311 for an entire orbital period

TL;DR

This study presents the first complete 28-day Swift/XRT monitoring of the Supergiant Fast X-ray Transient IGR J18483-0311 over an entire orbital period, providing valuable data to understand its accretion mechanisms.

Contribution

It applies a new clumpy wind model to explain the X-ray emission, offering insights into the accretion process in Supergiant Fast X-ray Transients.

Findings

X-ray emission explained by accretion from a clumpy stellar wind.

Observed X-ray light curve consistent with a spherically symmetric wind model.

Clump masses range from 10^{18}g to 5x10^{21}g.

Abstract

IGR J18483-0311 is an X-ray pulsar with transient X-ray activity, belonging to the new class of High Mass X-ray Binaries called Supergiant Fast X-ray Transients. This system is one of the two members of this class, together with IGR J11215-5952, where both the orbital (18.52d) and spin period (21s) are known. We report on the first complete monitoring of the X-ray activity along an entire orbital period of a Supergiant Fast X-ray Transient. These Swift observations, lasting 28d, cover more than one entire orbital phase consecutively. They are a unique data-set, which allows us to constrain the different mechanisms proposed to explain the nature of this new class of X-ray transients. We applied the new clumpy wind model for blue supergiants developed by Ducci et al. (2009), to the observed X-ray light curve. Assuming an eccentricity of e=0.4, the X-ray emission from this source can be explained in terms of the accretion from a spherically symmetric clumpy wind, composed of clumps with different masses, ranging from 10^{18}g to 5x 10^{21}g.