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 |
|---|---|
| Article number | A111 |
| Pages (from-to) | 1-7 |
| Number of pages | 7 |
| Journal | Astronomy & Astrophysics |
| Volume | 525 |
| DOIs | |
| Publication status | Published - 2011 |
Cite this
Zand, J., Galloway, D., & Ballantyne, D. (2011). Achromatic late-time variability in thermonuclear X-ray bursts: An accretion disk disrupted by a nova-like shell? Astronomy & Astrophysics, 525, 1-7. [A111]. https://doi.org/10.1051/0004-6361/201015556