Stellar Mass Black Holes in Young Galaxies

TL;DR

This paper models the cumulative energy output of stellar mass black holes in early galaxies, suggesting they could significantly influence galaxy evolution through distributed energy feedback.

Contribution

It introduces a new model for the growth and energy production of stellar mass black holes in primordial galaxies, considering uniform ISM density assumptions.

Findings

Estimated ~10^6 accreting black holes in young galaxies.

Potential energy release up to 10^61 ergs over billions of years.

Stellar black holes unlikely to reach Eddington luminosities at lower densities.

Abstract

We explore the potential cumulative energy production of stellar mass black holes in early galaxies. Stellar mass black holes may accrete substantially from the higher density interstellar media of primordial galaxies, and their energy release would be distributed more uniformly over the galaxy, perhaps providing a different mode of energy feedback into young galaxies than central supermassive black holes. We construct a model for the production and growth of stellar mass black holes over the first few gigayears of a young galaxy. With the simplifying assumption of a constant density of the ISM, n ~ 10^4 - 10^5 per cubic centimeter, we estimate the number of accreting stellar mass black holes to be ~ 10^6 and the potential energy production to be as high as 10^61 ergs over several billion years. For densities less than 10^5 per cubic centimeter, stellar mass black holes are unlikely to reach their Eddington limit luminosities. The framework we present could be incorporated in numerical simulations to compute the feedback from stellar-mass black holes with inhomogeneous, evolving interstellar media.