Stellar black holes: cosmic history and feedback at the dawn of the universe

TL;DR

This paper reviews the cosmic evolution of stellar black holes, emphasizing their increasing mass and prevalence at high redshifts and their significant feedback effects on the early universe's intergalactic medium.

Contribution

It highlights the overlooked role of black hole high-mass X-ray binaries in early universe reionization and provides theoretical and observational evidence for their cosmic evolution.

Findings

Black hole formation rate increases with redshift.

BH-HMXBs significantly heat and ionize the intergalactic medium.

Stellar black holes influence properties of faint high-redshift galaxies.

Abstract

Significant historic cosmic evolution for the formation rate of stellar black holes is inferred from current theoretical models of the evolution of massive stars, the multiple observations of compact stellar remnants in the near and distant universe, and the cosmic chemical evolution. The mean mass of stellar black holes, the fraction of black holes/neutron stars, and the fraction of black hole high mass X-ray binaries (BH-HMXBs)/solitary black holes increase with redshift. The energetic feedback from large populations of BH-HMXBs form in the first generations of star burst galaxies has been overlooked in most cosmological models of the reionization epoch of the universe. The powerful radiation, jets, and winds from BH-HMXBs heat the intergalactic medium over large volumes of space and keep it ionized until AGN take over. It is concluded that stellar black holes constrained the properties of the faintest galaxies at high redshifts. I present here the theoretical and observational grounds for the historic cosmic evolution of stellar black holes. Detailed calculations on their cosmic impact are presented elsewhere (Mirabel, Dijkstra, Laurent, Loeb, Pritchard, 2011).