On the cooling of neutron stars

Abstract

Results of a detailed numerical study of the cooling of neutron stars, undertaken to address the question of the existence of pion condensation in neutron star cores, are presented. Use is made of the best available opacities, conductivities, specific heats and neutrino emissivities to obtain cooling curves for different equations of state and masses, with general relativistic effects also taken into account. Models with a stiffer equation of state for neutron star matter are found to maintain lower surface temperatures, if the effects of pion condensation are ignored, while a softer equation of state results in stellar models of higher central density more likely to exhibit pion condensation. Curves for the detectability distance of the thermal neutron star as a function of its age are also presented, together with qualitative calculations of the effects of magnetic fields.