The formation and evolution of young low-mass stars within halos with high concentration of dark matter particles

TL;DR

This study explores how low-mass stars evolve within dense dark matter halos, revealing unique equilibrium states and potential for dark matter research based on stellar properties.

Contribution

It provides the first detailed numerical analysis of young low-mass star evolution in high dark matter density environments, including pre-main sequence behavior.

Findings

Stars in high DM densities halt collapse before reaching the main sequence.

Stars in lower DM densities continue collapsing and burn hydrogen more slowly.

Stellar temperature and luminosity strongly depend on dark matter particle properties.

Abstract

The formation and evolution of low-mass stars within dense halos of dark matter (DM) leads to evolution scenarios quite different from the classical stellar evolution. As a result of our detailed numerical work, we describe these new scenarios for a range of DM densities on the host halo, a range of scattering cross sections of the DM particles considered, and for stellar masses from 0.7 to 3 M_{\odot}. For the first time, we also computed the evolution of young low-mass stars in their Hayashi track in the pre-main sequence phase and found that, for high DM densities, these stars stop their gravitational collapse before reaching the main sequence, in agreement with similar studies on first stars. Such stars remain indefinitely in an equilibrium state with lower effective temperatures (|\Delta T_eff| > 10^3 K for a star of one solar mass), the annihilation of captured DM particles in their core being the only source of energy. In the case of lower DM densities, these proto-stars continue their collapse and progress through the main sequence burning hydrogen at a lower rate. A star of 1 M_{\odot} will spend a time greater than the current age of the universe consuming all the hydrogen in its core if it evolves in a halo with DM density \rho_{\chi}=10^9 GeV cm^-3. We also show the strong dependence of the effective temperature and luminosity of these stars on the characteristics of the DM particles and how this can be used as an alternative method for DM research.