Thermal Evolution of Rotating Neutron Stars

TL;DR

This paper models the thermal evolution of rotating neutron stars, showing how their cooling behavior varies with rotation frequency and resulting temperature anisotropies.

Contribution

It introduces a method to compute the structure and thermal evolution of rotating neutron stars using Einstein's equations and a relativistic mean field model.

Findings

Cooling rate depends on rotation frequency

Higher frequency stars exhibit temperature anisotropy

Rotation significantly affects neutron star thermal evolution

Abstract

In this work we consider the thermal evolution of rigidly rotating neutron stars. In order to perform such study we first calculate the structure of rotating objects, which is considerably more complicated than that of spherical objects. The structure of rotating neutron stars is obtained by solving Einstein's equation for a rotationally deformed fluid distributions. The numerical method used is based on the the KEH. The equation of state used for computing the neutron star structure and composition is a simple relativistic mean field model, with parameter set G300. With the structure of rotating neutron stars computed we calculate the thermal evolution of these objects. In order to do so, we re-derive the thermal evolution equations to account for the metric of a rotating object. The cooling of neutron stars with different frequencies is then calculated. We show that the cooling of the star strongly depends on the frequency of the object, with higher frequencies stars showing a substantial temperature difference between the equator and poles.