Strangeness, condensation, nucleon superfluidity, and cooling of neutron stars

Abstract

Results from a study of the cooling of neutron stars are presented. The paper uses a variety of equations of state and particularly examines the effects of 'exotic' matter (e.g., pion or kaon condensates, quark matter) at the center of the star. The effect of superfluidity in the core and crust is also studied. It is found that in order to fit the observed young neutron stars, the Crab, 3C 58, and RCW 103, superfluidity is required, but no exotic matter is needed. In order to fit the observed temperature of the Vela pulsar both superfluidity and some 'exotic' matter at the center are needed. It is concluded that Vela is a star with larger mass than the other three and hence has a higher density in the center, at which the exotica are produced.