Cooling of transiently accreting neutron stars

The radiation from transient low mass X-ray binaries in quiescence is mainly due to the cooling of the surface of the neutron star being heated during outbursts. This radiation has been observed with X-ray telescopes especially in recent years, and thus, important findings about the physical properties of the crust layers of neutron stars have been reached based on their cooling properties. To date, however, all the atmosphere models used in modeling this radiation have been developed under the assumption that neutron stars do not rotate in a relativistic sense. This is in contradiction with the high rotational frequencies of some of these neutron stars. With the studies carried out within the scope of our project, a new model, which takes into account the additional relativistic effects of rotation in modeling of surface radiation, has been applied for the first time and systematically to transient X-ray binaries. Thus, the effect of rotation on the cooling of neutron stars is examined for the first time, taking into account the relevant relativistic effects. As a result of the studies performed, the model applied to the cooling data of the neutron stars from 8 different low mass X-ray binaries, explains the data with the same statistical performance as the classic model, but gives a temperature value that is different up to 3%. Although this change appears to be systematic, it does not significantly affect the cooling curves of resources. We are planning to add the model we created to the model library of the XSPEC program with the publication of the studies made within the scope of the thesis.