Nuclear Pairing Gaps and Neutron Star Cooling

TL;DR

This paper investigates how nuclear pairing gaps influence neutron star cooling, demonstrating that adjusting proton gaps can align models with observed data and predict realistic neutron star mass distributions.

Contribution

It provides a consistent model of neutron star cooling using microscopic nuclear equations of state and modified pairing gaps, improving understanding of neutron star thermal evolution.

Findings

Cooling data can be explained with reduced proton gaps

No neutron 3P2 pairing needed for current data

Predicts realistic neutron star mass distribution

Abstract

We study the cooling of isolated neutron stars with particular regard to the importance of nuclear pairing gaps. A microscopic nuclear equation of state derived in the Brueckner-Hartree-Fock approach is used together with compatible neutron and proton pairing gaps. We then study the effect of modifying the gaps on the final deduced neutron star mass distributions. We find that a consistent description of all current cooling data can be achieved and a reasonable neutron star mass distribution can be predicted employing the (slightly reduced by about 40\%) proton 1S0 Bardeen-Cooper-Schrieffer (BCS) gaps and no neutron 3P2 pairing.