The Very First Population III Stars and Their Relation to Bright z≈6 Quasars

摘要

We discuss the link between dark matter halos hosting the first Population III stars that formed at redshift z>40 and the rare, massive, halos that are generally considered to host bright z6 quasars. We show that within the typical volume occupied by one bright high-z QSO the remnants of the first several thousand Population III stars formed do not end up in the most massive halos at z6, but rather live in a large variety of environments. The black hole seeds planted by these very first Population III stars can easily grow to M>109.5 M by z = 6 assuming Eddington accretion with radiative efficiency 0.1. Therefore, quenching of the accretion is crucial to avoid an overabundance of supermassive black holes. We implement a simple feedback model for the growth of the seeds planted by Pop III stars and obtain a z6 black hole mass function consistent with the observed QSO luminosity function.