Growth of Light Seed Black Holes in the Early Universe

TL;DR

This study demonstrates through high-resolution cosmological simulations that light seed black holes from Population III stars can rapidly grow in the early universe, potentially explaining the origin of supermassive black holes observed at high redshifts.

Contribution

The paper introduces a novel black hole seeding method and uses advanced zoom-in simulations to show rapid growth of light seed black holes in the early universe.

Findings

Light seed black holes can grow to ~10^4 solar masses quickly.

The growth supports their role as progenitors of observed supermassive black holes.

Results align with JWST observations and future gravitational wave detections.

Abstract

Observations from the James Webb Space Telescope (JWST) have uncovered supermassive black holes (SMBHs) with masses exceeding $10^6 \mathrm{M}_{\odot}$ at redshifts $z > 8$, posing significant challenges to existing models of early black hole formation and growth. Here we show, in a fully cosmological setting, that light seed black holes (LSBHs), remnants of Population III stars, can grow rapidly to $\sim10^4 \mathrm{M}_{\odot}$ in the early Universe. This growth is enabled by our novel black hole seeding prescription and the unprecedented resolution of our zoom-in cosmological simulations, which resolve the dense environments necessary for efficient accretion. Our results provide robust evidence that LSBHs can attain the masses required to serve as the dominant progenitors of the SMBH population observed at later cosmic epochs. These findings have far-reaching implications for the interpretation of JWST observations and future gravitational wave detections with LISA.