Supermassive Dark Stars: Detectable in JWST

TL;DR

This paper proposes that supermassive dark stars, powered by dark matter annihilation, could grow to enormous sizes, be detectable by JWST, and serve as seeds for supermassive black holes, revealing a new stellar evolution phase.

Contribution

It introduces the concept of supermassive dark stars powered by dark matter, detailing their growth, properties, and potential detectability with JWST, a novel aspect of early universe stellar evolution.

Findings

Supermassive dark stars can reach masses of 10^5-10^7 solar masses.

These stars are very luminous, exceeding 10^9 solar luminosities.

They are detectable with JWST under reasonable parameters.

Abstract

The first phase of stellar evolution in the history of the Universe may be Dark Stars, powered by dark matter heating rather than by nuclear fusion. Weakly Interacting Massive Particles, which may be their own antipartners, collect inside the first stars and annihilate to produce a heat source that can power the stars for millions to billions of years. In this paper we show that these objects can grow to be supermassive dark stars (SMDS) with masses $\gtrsim (10^5-10^7) \msun$. The growth continues as long as dark matter heating persists, since dark stars are large and cool (surface temperature $\lesssim 5\times 10^4$K) and do not emit enough ionizing photons to prevent further accretion of baryons onto the star. The dark matter may be provided by two mechanisms: (1) gravitational attraction of dark matter particles on a variety of orbits not previously considered, and (2) capture of WIMPs due to elastic scattering. Once the dark matter fuel is exhausted, the SMDS becomes a heavy main sequence star; these stars eventually collapse to form massive black holes that may provide seeds for supermassive black holes in the Universe. SMDS are very bright, with luminosities exceeding $(10^9-10^{11}) L_\odot$. We demonstrate that for several reasonable parameters, these objects will be detectable with JWST. Such an observational discovery would confirm the existence of a new phase of stellar evolution powered by dark matter.