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arXiv · 1009.5359

Achromatic late-time variability in thermonuclear X-ray bursts - an accretion disk disrupted by a nova-like shell?

J. J. M. in 't Zand·D. K. Galloway·D. R. Ballantyne
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Abstract

An unusual Eddington-limited thermonuclear X-ray burst was detected from the accreting neutron star in 2S 0918-549 with the Rossi X-ray Timing Explorer. The burst commenced with a brief (40 ms) precursor and maintained near-Eddington fluxes during the initial 77 s. These characteristics are indicative of a nova-like expulsion of a shell from the neutron star surface. Starting 122 s into the burst, the burst shows strong (87 +/- 1% peak-to-peak amplitude) achromatic fluctuations for 60 s. We speculate that the fluctuations are due to Thompson scattering by fully-ionized inhomogeneities in a resettling accretion disk that was disrupted by the effects of super-Eddington fluxes. An expanding shell may be the necessary prerequisite for the fluctuations.

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J. J. M. in 't Zand, D. K. Galloway, D. R. Ballantyne. 2010-09-27. Achromatic late-time variability in thermonuclear X-ray bursts - an accretion disk disrupted by a nova-like shell?. https://doi.org/10.1051/0004-6361/201015556

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