Dark Matter Capture in the First Stars: a Power Source and Limit on Stellar Mass

TL;DR

This paper explores how dark matter annihilation and capture could power the first stars, influence their evolution, and provide constraints on dark matter properties and stellar masses.

Contribution

It introduces the role of dark matter capture in prolonging dark star lifetimes and constraining the mass of the first stars based on dark matter interactions.

Findings

Dark matter annihilation can dominate stellar luminosity under certain conditions.

Dark matter capture may extend the lifetime of dark stars.

Observations of first stars can constrain dark matter properties.

Abstract

The annihilation of weakly interacting massive particles can provide an important heat source for the first (Pop. III) stars, potentially leading to a new phase of stellar evolution known as a "Dark Star". When dark matter (DM) capture via scattering off of baryons is included, the luminosity from DM annihilation may dominate over the luminosity due to fusion, depending on the DM density and scattering cross-section. The influx of DM due to capture may thus prolong the lifetime of the Dark Stars. Comparison of DM luminosity with the Eddington luminosity for the star may constrain the stellar mass of zero metallicity stars; in this case DM will uniquely determine the mass of the first stars. Alternatively, if sufficiently massive Pop. III stars are found, they might be used to bound dark matter properties.