Quantum ion thermodynamics in liquid interiors of white dwarfs

TL;DR

This paper develops an analytic approximation for quantum ion energies in white dwarf interiors, revealing how quantum effects influence their thermodynamics, cooling, and pulsation properties.

Contribution

It provides a new analytic model for quantum ion thermodynamics in white dwarf liquid interiors, enhancing understanding of their physical properties.

Findings

Quantum effects impact heat capacity and cooling of white dwarfs.

Thermal and pulsation properties are affected by ionic quantum effects.

Model applies to dense helium and carbon core white dwarfs.

Abstract

We present an accurate analytic approximation for the energy of a quantum one-component Coulomb liquid of ions in a uniform electron background which has been recently calculated from first principles (Baiko 2019). The approximation enables us to develop in an analytic form a complete thermodynamic description of quantum ions in a practically important range of mass densities at temperatures above crystallization. We show that ionic quantum effects in liquid cores of white dwarfs (WDs) affect heat capacity, cooling, thermal compressibility, pulsation frequencies and radii of sufficiently cold WDs, especially with relatively massive helium and carbon cores.