The Growth of the Stellar Seeds of Supermassive Black Holes

TL;DR

This paper reviews recent theoretical and simulation advances supporting the idea that supermassive stars can grow rapidly and collapse into seed black holes, explaining the origin of supermassive black holes in the early universe.

Contribution

It synthesizes recent theoretical and cosmological simulation findings that bolster the supermassive star seed hypothesis for black hole formation.

Findings

Supermassive stars can reach >100,000 solar masses despite radiation feedback.

High molecule-dissociating radiation fluxes may be common in the early universe.

Most supermassive black holes may originate from supermassive stars at high redshifts.

Abstract

One of the most promising explanations for the origin of the billion solar mass black holes (BHs) inferred to power quasars at redshifts z > 6 is that supermassive stars (SMSs) with masses > 10,000 solar masses collapse to form the seed BHs from which they grow. Here we review recent theoretical advances which provide support for this scenario. Firstly, given sufficiently high accretion rates of gas into the cores of primordial protogalaxies, it appears that neither the high energy radiation emitted from the stellar surface nor the limited lifetime of SMSs can prevent their growth to masses of up to > 100,000 solar masses. Secondly, recent cosmological simulations suggest that the high fluxes of molecule-dissociating radiation which may be required in order to achieve such high accretion rates may be more common in the early universe than previously thought. We conclude that the majority of supermassive BHs may originate from SMSs at high redshifts.