Physical Sciences and Mathematics Commons^™

Cooling Of The Quasi-Persistent Neutron Star X-Ray Transients Ks 1731-260 And Mxb 1659-29, Edward M. Cackett, Rudy Wijnands, Manuel Linares, Jon M. Miller, Jeroen Homan, Walter H. G. Lewin

Physics and Astronomy Faculty Research Publications

We present Chandra and XMM-Newton X-ray observations that monitor the neutron star cooling of the quasi-persistent neutron star X-ray transients KS 1731-260 and MXB 1659-29 for approximately 4 yr after these sources returned to quiescence from prolonged outbursts. In both sources the outbursts were long enough to significantly heat the neutron star crust out of thermal equilibrium with the core. We analyse the X-ray spectra by fitting absorbed neutron star atmosphere models to the observations. The results of our analysis strengthen the preliminary findings of Wijnands et al. that in both sources the neutron star crust cools down very rapidly …