Thermalisation time and specific heat of neutron stars crust

TL;DR

This paper models the thermalisation process of neutron star crusts by solving the heat transport equation with microscopic specific heat inputs, revealing the significant impact of pairing correlations and nuclear clusters on cooling times.

Contribution

It introduces a detailed microscopic calculation of the crust's specific heat using Hartree-Fock-Bogoliubov theory and analyzes how pairing and cluster structures influence thermalisation.

Findings

Pairing correlations significantly reduce thermalisation time.

Nuclear clusters affect the surface temperature evolution.

Crust composition impacts neutron star cooling behavior.

Abstract

We discuss the thermalisation process of the neutron stars crust described by solving the heat transport equation with a microscopic input for the specific heat of baryonic matter. The heat equation is solved with initial conditions specific to a rapid cooling of the core. To calculate the specific heat of inner crust baryonic matter, i.e., nuclear clusters and unbound neutrons, we use the quasiparticle spectrum provided by the Hartree-Fock-Bogoliubov approach at finite temperature. In this framework we analyse the dependence of the crust thermalisation on pairing properties and on cluster structure of inner crust matter. It is shown that the pairing correlations reduce the crust thermalisation time by a very large fraction. The calculations show also that the nuclear clusters have a non-negligible influence on the time evolution of the surface temperature of the neutron star.