The distance and internal composition of the neutron star in EXO 0748-676 with XMM-Newton
arXiv:1007.0647 · doi:10.1111/j.1365-2966.2011.18443.x
Abstract
Recently, the neutron star X-ray binary EXO 0748-676 underwent a transition to quiescence. We analyzed an XMM-Newton observation of this source in quiescence, where we fitted the spectrum with two different neutron-star atmosphere models. From the fits we constrained the allowed parameter space in the mass-radius diagram for this source for an assumed range of distances to the system. Comparing the results with different neutron-star equations of state, we constrained the distance to EXO 0748-676. We found that the EOS model 'SQM1' is rejected by the atmosphere model fits for the known distance, and the 'AP3' and 'MS1' is fully consistent with the known distance.
6 pages, 7 figures, 2 tables, submitted to MNRAS on June 20, 1010