Towards an empirical unified crust-core description of neutron stars

TL;DR

This paper develops a unified density functional approach to describe both the crust and core of neutron stars, linking terrestrial nuclear experiments with astrophysical models to improve understanding of neutron star phenomena.

Contribution

It introduces an extended density functional scheme that models non-homogeneous crust matter within the same framework as the core, grounded in empirical nuclear data.

Findings

Scheme successfully describes nuclei in the crust

Model aligns with nuclear experimental observables

Provides a consistent crust-core description for neutron stars

Abstract

Understanding the properties of the crust and the core as well as its interface is essential for accurate astrophysical modeling of phenomena such as glitches, X-ray bursts or oscillations in neutron stars. To study the crust-core properties, it is crucial to develop a unified and consistent scheme to describe both the clusterized matter in the crust and homogeneous matter in the core. The low density regime in the neutron star crust is accessible to terrestrial nuclear experiments. In order to develop a consistent description of the crust and the core of neutron stars within the same formalism, we use a density functional scheme, with the model coefficients in homogeneous matter related directly to empirical nuclear observables. In this work, we extend this scheme to non-homogeneous matter to describe nuclei in the crust. We then test this scheme against nuclear observables.