Thermal relaxation and cooling of quark stars with a strangelet crust

Abstract

Context. In this article we explore the cooling of isolated quark stars. These objects are structured from a homogeneous quark matter core and crusted by ordinary matter or by strangelets. Aims. Our main purpose is to quantify the effects of a strangelet crust on the cooling and relaxation times of these strange stars. Methods. We adopt two kinds of crust: (i) a crust made of purely nuclear matter following the Baym-Pethick-Sutherland equation of state (EOS) and (ii) a crust made of nuggets of strange quark matter (strangelets). Both models have the same quark matter core, described by the MIT bag model EOS. Our study also includes the possible effects of color superconductivity in the quark core. Results. We have found that objects with a strangelet crust have a significantly different thermal relaxation time.