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arXiv · 1812.04483

On the origin of supergiant fast X-ray transients

Swetlana Hubrig·Lara Sidoli·Konstantin A. Postnov·Markus Schöller·Alexander F. Kholtygin·Silva P. Jarvinen
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Abstract

A fraction of high-mass X-ray binaries are supergiant fast X-ray transients. These systems have on average low X-ray luminosities, but display short flares during which their X-ray luminosity rises by a few orders of magnitude. The leading model for the physics governing this X-ray behaviour suggests that the winds of the donor OB supergiants are magnetized. In agreement with this model, the first spectropolarimetric observations of the SFXT IGR J11215-5952 using the FORS2 instrument at the Very Large Telescope indicate the presence of a kG longitudinal magnetic field. Based on these results, it seems possible that the key difference between supergiant fast X-ray transients and other high-mass X-ray binaries are the properties of the supergiant's stellar wind and the physics of the wind's interaction with the neutron star magnetosphere.

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Swetlana Hubrig, Lara Sidoli, Konstantin A. Postnov, Markus Schöller, Alexander F. Kholtygin, Silva P. Jarvinen. 2018-12-09. On the origin of supergiant fast X-ray transients. https://doi.org/10.1017/s1743921318008426

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