Quark core impact on hybrid star cooling

TL;DR

This study explores how the microscopic properties of quark cores in hybrid stars influence their thermal evolution, using simple models to match observed neutron star cooling data and inform future quark matter research.

Contribution

It introduces a straightforward modeling approach to assess the impact of quark core properties on hybrid star cooling, including color superconductivity effects.

Findings

Certain microscopic parameters yield models consistent with observed cooling data.

Color superconductivity influences the thermal evolution significantly.

The approach helps constrain quark matter properties in hybrid stars.

Abstract

In this paper we investigate the thermal evolution of hybrid stars, objects composed of a quark matter core, enveloped by ordinary hadronic matter. Our purpose is to investigate how important are the microscopic properties of the quark core to the thermal evolution of the star. In order to do that we use a simple MIT bag model for the quark core, and a relativistic mean field model for the hadronic envelope. By choosing different values for the microscopic parameters (bag constant, strange quark mass, strong coupling constant) we obtain hybrid stars with different quark core properties. We also consider the possibility of color superconductivity in the quark core. With this simple approach, we have found a set of microscopic parameters that lead to a good agreement with observed cooling neutron stars. Our results can be used to obtain clues regarding the properties of the quark core in hybrid stars, and can be used to refine more sophisticated models for the equation of state of quark matter.