Thermal conductivity and impurity scattering in the accreting neutron star crust

TL;DR

This paper uses Path Integral Monte Carlo to accurately compute electron thermal conductivity in neutron star crusts, revealing higher impurity scattering rates than previously estimated, which affects thermal relaxation models.

Contribution

It introduces a PIMC-based method to calculate electron scattering and thermal conductivity in multi-component ion plasmas of neutron star crusts, improving accuracy over prior models.

Findings

Scattering rate is 2-4 times higher than earlier estimates.

Impacts interpretation of thermal relaxation in accreting neutron stars.

Provides insights into crust composition and nuclear reactions.

Abstract

We calculate the thermal conductivity of electrons for the strongly correlated multi-component ion plasma expected in the outer layers of neutron star's crust employing a Path Integral Monte Carlo (PIMC) approach. This allows us to isolate the low energy response of the ions and use it to calculate the electron scattering rate and the electron thermal conductivity. We find that the scattering rate is enhanced by a factor 2-4 compared to earlier calculations based on the simpler electron-impurity scattering formalism. This findings directly impacts the interpretation of thermal relaxation observed in transiently accreting neutron stars and has implications for the composition and nuclear reactions in the crust that occur during accretion.