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 caused by 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.
Original language | English |
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Article number | A111 |
Pages (from-to) | 1-7 |
Number of pages | 7 |
Journal | Astronomy & Astrophysics |
Volume | 525 |
DOIs | |
Publication status | Published - 2011 |