Long-duration neutron star X-ray transients in quiescence: the Chandra observation of KS 1731-260

Abstract

I will briefly discuss the implications of the recent quiescent Chandra observation of the long-duration neutron star transient KS 1731-260 (Wijnands et al. 2001a) on models for quiescent systems other than the Brown et al. (1998) cooling neutron star model. However, the Chandra results are not very constraining; for those models to be consistent with the data, one only has to assume that the system parameters of KS 1731-260 (e.g., the neutron star spin rate and magnetic field properties; orbital parameters) are very similar to those of the other systems. I will also discuss the available quiescent data of other long-duration neutron star transients in the context of the Brown et al. (1998) model.