Joule heating in the cooling of magnetized neutron stars

TL;DR

This paper presents 2D simulations of magnetized neutron star cooling, highlighting the significant impact of Joule heating and magnetic field decay on thermal evolution and temperature anisotropy.

Contribution

It introduces detailed 2D models incorporating microphysics and magnetic field decay to study their effects on neutron star cooling and temperature distribution.

Findings

Joule heating can dominate the thermal evolution in strongly magnetized neutron stars.

Magnetic field decay significantly influences cooling curves and temperature anisotropy.

Magnetic field geometry affects the surface temperature distribution during different evolutionary stages.

Abstract

We present 2D simulations of the cooling of neutron stars with strong magnetic fields (B \geq 10^{13} G). We solve the diffusion equation in axial symmetry including the state of the art microphysics that controls the cooling such as slow/fast neutrino processes, superfluidity, as well as possible heating mechanisms. We study how the cooling curves depend on the the magnetic field strength and geometry. Special attention is given to discuss the influence of magnetic field decay. We show that Joule heating effects are very large and in some cases control the thermal evolution. We characterize the temperature anisotropy induced by the magnetic field for the early and late stages of the evolution of isolated neutron stars.