Premature Black Hole Death of Population III Stars by Dark Matter

TL;DR

This paper explores how dark matter interactions could cause Population III stars to prematurely collapse into black holes, affecting early universe evolution and observable signals.

Contribution

It introduces a novel mechanism where dark matter interactions lead to early black hole formation from Population III stars, impacting cosmic reionization and gravitational wave signals.

Findings

Dark matter interactions can cause early black hole formation from Population III stars.

Potential observational signatures include altered reionization history and gravitational wave events.

Pair-instability supernovae observations can constrain the premature black hole formation scenario.

Abstract

Population III stars were the first generation of stars, formed in minihalos of roughly primordial element abundances, and therefore metal-free. They are thought to have formed at the cores of dense dark matter clouds. Interactions between baryons and dark matter can therefore have had an important impact on their evolution. In this paper we consider the capture of non- or weakly-annihilating dark matter by these early massive stars. In a wide region of parameter space, interactions of dark matter with baryons lead to premature death of the star as a black hole. We sketch how this modification of the standard evolutionary history of Population III stars might impact the epoch of reionisation, by modifying the amount of UV emission, the transition to Population II star formation, and the X-ray and radio emission from accretion onto the black hole remnants. Signals of massive black holes originating from Population III stars could be observed through gravitational waves from their mergers. Finally, the observation of pair-instability supernovae could effectively preclude premature black hole death across a wide range of parameter space, ranging in mass from $m_{DM} \sim 0.1\text{ GeV}$ to $m_{DM} \sim m_{\rm Pl}$.