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arXiv · 1109.6165

Swift/XRT monitoring of the candidate Supergiant Fast X-ray Transient IGR J16418-4532

P. Romano·V. Mangano·L. Ducci·P. Esposito·P. A. Evans·S. Vercellone·J. A. Kennea·D. N. Burrows·N. Gehrels
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Abstract

We report on the Swift monitoring of the candidate supergiant fast X-ray transient (SFXT) IGR J16418-4532, for which both orbital and spin periods are known (~3.7d and ~1250s, respectively). Our observations, for a total of ~43ks, span over three orbital periods and represent the most intense and complete sampling of the light curve of this source with a sensitive X-ray instrument. With this unique set of observations we can address the nature of this transient. By applying the clumpy wind model for blue supergiants to the observed X-ray light curve, and assuming a circular orbit, 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 ~5E16 g to 1E21g. Our data suggest, based on the X-ray behaviour, that this is an intermediate SFXT.

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P. Romano, V. Mangano, L. Ducci, P. Esposito, P. A. Evans, S. Vercellone, J. A. Kennea, D. N. Burrows, N. Gehrels. 2011-09-28. Swift/XRT monitoring of the candidate Supergiant Fast X-ray Transient IGR J16418-4532. https://doi.org/10.1111/j.1365-2966.2011.19916.x

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