A theoretical study of heavy nucleus-acoustic waves in white dwarf core environments.

A quantum hydrodynamic model formalism is semi-analytically offered to explore the propagatory and dispersive nature of heavy nucleus-acoustic waves (NAWs) in the completely degenerate (CD) oxygen–neon (ONe) and CO white dwarf (WD) cores. It includes their surrounding nearly degenerate (ND) transition regions. It has classical light nuclear species (LNS), heavy nuclear species (HNS) and quantum electrons in a spherically symmetric geometry. The electronic equation of state here considers the temperature degeneracy, interaction of electrons with the surrounding electrons and nuclei, exchange interaction and correlation interaction effects collectively. A methodical application of normal spherical mode analysis yields a generalised linear sextic dispersion relation of a unique mathematical type. A numerical illustrative platform shows the NAW propagatory and dispersive behaviours of current interest elaborately. It is interesting to find that the NAW is composed of multiple-frequency acoustic wave-spectral components. It is seen that both the CD core of the ONe WD and the ND region around the core are more sensitive to the temperature than the CO WD case. We finally indicate the tentative applicability of the investigated results with a special mention of compact astronomic situations. [ABSTRACT FROM AUTHOR]