Stability of nucleus-acoustic waves in completely degenerate white dwarf cores and their nearly degenerate ambience

TL;DR

This paper investigates the stability and propagation characteristics of nucleus-acoustic waves in the degenerate cores of white dwarfs, considering quantum plasma effects and temperature influences, with implications for asteroseismology.

Contribution

It introduces a comprehensive model of nucleus-acoustic waves in white dwarf cores accounting for quantum degeneracy, temperature effects, and plasma multiparametric dependencies.

Findings

NAW exhibit growth near transcritical wave zones

Temperature influences NAW growth differently in ONe and CO WDs

The model aids in understanding white dwarf internal structures via asteroseismology

Abstract

We analyze the propagatory nucleus-acoustic wave (NAW) modes excitable in the completely degenerate (CD) core and in its nearly degenerate (ND) ambience of the ONe and CO white dwarfs (WDs). It is based on three-component spherical hydrodynamic quantum plasma consisting of tiny non-thermal quantum electrons, classical thermal light nuclear species (LNS), and classical thermal heavy nuclear species (HNS). The inner concentric layer-wise electronic pressures are judiciously modelled. The electronic energy distribution governed by the Fermi-Dirac (FD) thermostatistical distribution law involves both the thermodynamical temperature and chemical potential. Our exploration emphasizes on the transition state between the thermodynamical temperature and the Fermi temperature for the borderline regions of intermediate degeneracy. A normal spherical mode analysis procedurally yields a sextic generalized linear dispersion relation highlighting the plasma multiparametric dependency of the NAW-features. A numerical illustrative platform is constructed to investigate the full NAW propagatory and dispersive behaviours. We demonstrate that the NAW in ONe (CO) WDs exhibits sensible growth characteristics at near the transcritical (supercritical) wave zone. The temperature-sensitivity of the NAW-growth is more (less) prominent in ONe (CO) WDs. It could be hopefully useful to see the internal structure of compact astroobjects from the asteroseismic probe-perspective of collective quantum interaction processes.