Neutron star crust cooling in KS 1731-260: the influence of accretion outburst variability on the crustal temperature evolution
arXiv:1606.01923 · doi:10.1093/mnras/stw1799
Abstract
Using a theoretical model, we track the thermal evolution of a cooling neutron star crust after an accretion induced heating period with the goal of constraining the crustal parameters. We present for the first time a crust cooling model that takes into account detailed variability during the full outburst based on the observed light curve. We apply our model to KS 1731-260. The source was in outburst for 12 years during which it was observed to undergo variations on both long (years) and short (days-weeks) timescales. Our results show that KS 1731-260 does not reach a steady state profile during the outburst due to fluctuations in the derived accretion rate. Additionally, long time-scale outburst variability mildly affects the complete crust cooling phase, while variations in the final months of the outburst strongly influence the first 40 days of the calculated cooling curve. We discuss the consequences for estimates of the neutron star crust parameters, and argue that detailed modelling of the final phase of the outburst is key to constraining the origin of the shallow heat source.
6 pages, 3 figures, supplemental online video available at https://www.youtube.com/watch?v=9eUEe6rBUM4 . Accepted for publication in MNRAS Letters
References in corpus (9)
- Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
- Disordered nuclear pasta, magnetic field decay, and crust cooling in neutron stars
- Models of crustal heating in accreting neutron stars
- Six new candidate ultracompact X-ray binaries
- Cooling of the quasi-persistent neutron star X-ray transients KS 1731-260 and MXB 1659-29
- Phase separation in the crust of accreting neutron stars
- Rapid Cooling of the Neutron Star in the Quiescent Super-Eddington Transient XTE J1701-462
- A strongly heated neutron star in the transient Z source MAXI J0556-332
- Probing the Crust of the Neutron Star in EXO 0748-676
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