Temporal Studies of Supergiant Fast X-ray Transients

TL;DR

This paper investigates the temporal behavior of supergiant fast X-ray transients (SFXTs), revealing a new orbital period and flaring activity, which enhances understanding of their place in high-mass X-ray binary systems and their accretion processes.

Contribution

It reports the discovery of a 51.47-day orbital period in XTE J1739-302 and identifies new flaring activity in several SFXTs using INTEGRAL and RXTE data.

Findings

Discovered a 51.47-day orbital period in XTE J1739-302.

Detected new flaring activity in SAX J1818.6-1703, IGR J16479-4514, and IGR J16465-4507.

Enhanced understanding of SFXT temporal behavior and accretion mechanisms.

Abstract

SFXTs are a new class of HMXB unveiled by INTEGRAL. They are extreme systems characterised by very short outbursts (a few hours) and extreme X-ray luminosity dynamic ranges (~10^{4}). Ten confirmed systems are currently known and have shown parallels with both Sg-XRBs and Be-XRBs. Temporal studies across all timescales are key to understanding both the place of SFXTs within the HMXB hierarchy and the accretion mechanisms at work within the objects. Here we present the discovery of a new 51.47 \pm 0.02 day orbital period in the SFXT XTE J1739$-$302 using INTEGRAL observations. We also present a higher time resolution study of the SFXTs SAX J1818.6-1703, IGR J16479-4514 and IGR J16465-4507 using RXTE that shows newly discovered flaring activity.