Astrophysics and Astronomy Commons^™

Continued Cooling Of The Crust In The Neutron Star Low-Mass X-Ray Binary Ks 1731-260, Edward M. Cackett, Edward F. Brown, Andrew Cumming, Nathalie Degenaar, Jon M. Miller, Rudy Wijnands

Physics and Astronomy Faculty Research Publications

Some neutron star low-mass X-ray binaries have very long outbursts (lasting several years) which can generate a significant amount of heat in the neutron star crust. After the system has returned to quiescence, the crust then thermally relaxes. This provides a rare opportunity to study the thermal properties of neutron star crusts, putting constraints on the thermal conductivity and hence the structure and composition of the crust. KS 1731-260 is one of only four systems where this crustal cooling has been observed. Here, we present a new Chandra observation of this source approximately eight years after the end of the …

Optical/Infrared Observations Of The X-Ray Burster Ks1731-260 In Quiescence, C. Zurita, E. Kuulkers, R. M. Bandyopadhyay, E. M. Cackett, P. J. Groot, J. A. Orosz, M. A. P. Torres, R. Wijnands

Physics and Astronomy Faculty Research Publications

Aims. We performed an optical/infrared study of the counterpart of the low-mass X-ray binary KS 1731–260 to test its identification and obtain information about the donor.

Methods. Optical and infrared images of the counterpart of KS 1731–260 were taken in two different epochs (2001 and 2007) after the source returned to quiescence in X-rays. We compared these observations with those obtained when KS 1731–260 was still active.

Results. We confirm the identification of KS 1731–260 with the previously proposed counterpart and improve its position to α = 17:34:13.46 and δ = -26:05:18.60. The H-band magnitude of this …

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 …