Revisiting the Impact of Axions in the Cooling of White Dwarfs

TL;DR

This paper investigates how axion particles could influence white dwarf cooling by incorporating axion emission into stellar evolution models, aiming to refine constraints on axion properties through white dwarf luminosity observations.

Contribution

It introduces self-consistent stellar evolution computations that include axion emission effects, providing a more accurate assessment of axion impact on white dwarf cooling.

Findings

Axion emission significantly affects white dwarf cooling rates.

The modified luminosity function can help constrain axion properties.

Self-consistent models improve previous estimates of axion influence.

Abstract

It has been shown that the shape of the luminosity function of white dwarfs can be a powerful tool to check for the possible existence of DFSZ-axions. In particular, Isern et al. (2008) showed that, if the axion mass is of the order of a few meV, then the white dwarf luminosity function is sensitive enough to detect their existence. For axion masses of about $m_a > 5$ meV the axion emission can be a primary cooling mechanism for the white dwarf and the feedback of the axion emission into the thermal structure of the white dwarf needs to be considered. Here we present computations of white dwarf cooling sequences that take into account the effect of axion emission in a self consistent way by means of full stellar evolution computations. Then, we study and discuss the impact of the axion emission in the white dwarf luminosity function.