Cooling of dark neutron stars

TL;DR

This paper investigates how dark matter influences the thermal evolution of neutron stars, revealing that dark matter alters their structure and cooling behavior, with potential observational signatures.

Contribution

It introduces a comprehensive model combining realistic nuclear physics with variable dark matter content to study neutron star cooling.

Findings

Dark matter modifies nuclear density profiles in neutron stars.

Dark matter presence can lead to very massive, slow-cooling stars.

It can also produce very light, fast-cooling stars.

Abstract

We study the cooling of isolated dark-matter-admixed neutron stars, employing a realistic nuclear equation of state and realistic nuclear pairing gaps, together with fermionic dark matter of variable particle mass and dark-matter fraction. The related parameter space is scanned for the stellar structural and cooling properties. We find that a consistent description of all current cooling data requires fast direct Urca cooling and reasonable proton 1S0 gaps. Dark matter affects the cooling properties by a modification of the nuclear density profiles, but also changes stellar radius and maximum mass. Possible signals of a large dark matter content could be a very massive but slow-cooling star or a very light but fast-cooling star.