Equilibrium structure of white dwarfs at finite temperatures

TL;DR

This paper investigates how finite temperatures influence the equilibrium structure of white dwarfs by incorporating temperature effects into the Chandrasekhar equation of state and analyzing resulting mass-radius relations.

Contribution

It introduces a model that accounts for finite temperature effects in white dwarf structure calculations, extending previous degenerate models.

Findings

Finite temperature affects the pressure-density relationship in white dwarfs.

Mass-radius relations vary significantly with temperature changes.

Results align with observational data from SDSS DR4.

Abstract

Recently, it has been shown by S.~M. de Carvalho et al. (2014) that the deviations between the degenerate case and observations were already evident for 0.7-0.8 M$_{\odot}$ white dwarfs. Such deviations were related to the neglected effects of finite temperatures on the structure of a white dwarf. Therefore, in this work by employing the Chandrasekhar equation of state taking into account the effects of temperature we show how the total pressure of the white dwarf matter depends on the mass density at different temperatures. Afterwards we construct equilibrium configurations of white dwarfs at finite temperatures. We obtain the mass-radius relations of white dwarfs for different temperatures by solving the Tolman-Oppenheimer-Volkoff equation, and compare them with the estimated masses and radii inferred from the Sloan Digital Sky Survey Data Release 4.