Neutrino luminosities and heat capacities of neutron stars in analytic form

TL;DR

This paper provides analytic formulas for neutrino luminosities and heat capacities of neutron stars, aiding the interpretation of observational data and understanding of neutron star core properties.

Contribution

It introduces simplified analytic approximations for neutrino emissions and heat capacities of neutron stars, applicable across various equations of state.

Findings

Analytic approximations for neutrino luminosities and heat capacities.

Application to nine neutron stars considering magnetic fields and light elements.

Facilitates investigation of superfluid properties in neutron star cores.

Abstract

We derive analytic approximations for the neutrino luminosities and the heat capacities of neutron stars with isothernal nucleon cores as functions of the mass and radius of stars. The neutrino luminosities are approximated for the three basic neutrino emission mechanisms, and the heat capacities for the five basic combinations of the partial heat capacities. The approximations are valid for for a wide class of equations of state of dense nucleonmatter. The results significantly simplify the theoretical interpretation of observations of cooling neutron stars as well as of quasistationary thermal states of neutron stars in X-ray transients. For illustration, we present an analysis of the neutrino cooling functions of nine isolated neutron stars taking into account the effects of their magnetic fields and of the presence of light elements in their heat blanketing envelopes. These results allow one to investigate the superfluid properties of neutron star cores.