Swift observations of IGRJ16479-4514 in outburst

TL;DR

This paper reports Swift observations of IGR J16479-4514's outbursts, compares recent and past events, and discusses a potential common mechanism affecting accretion in this supergiant fast X-ray transient.

Contribution

It provides the first comparison of multiple outbursts of IGR J16479-4514 and suggests a shared accretion modulation mechanism across events.

Findings

Similar decay patterns in 2005, 2008, and 2009 outbursts

Evidence of an X-ray eclipse in 2008

Potential common accretion mechanism

Abstract

The supergiant fast X-ray transient source IGR J16479-4514 was observed in outburst two times with Swift. Its quiescent state was investigated in-depth only once in 2008 through a relatively long pointed observation with XMM-Newton. The latter observation was taken about 1.7 days after the outburst in 2008, and showed an X-ray eclipse-like event, likely caused by the supergiant companion. At present, this is the only supergiant fast X-ray transient that displayed an evidence for an X-ray eclipse. Here we carry out a comparison between the most recent outburst of IGRJ16479-4514, caught by Swift on 29 January 2009 and those detected previously from this source. The decay from the outbursts in 2005, 2008 and 2009 presents many similarities, and suggests a common mechanism that modulates the mass accretion rate onto the neutron star in IGRJ16479-4514.