Black holes in the early Universe

Abstract

Abstract.The existence of massive black holes was postulated in the sixties, when the first quasars were discovered. In the late nineties their reality was proven beyond doubt, in the Milky way and a handful nearby galaxies. Since then, enormous theoretical and observational efforts have been made to understand the astrophysics of massive black holes. We have discovered that some of the most massive black holes known, weighing billions of solar masses, powered luminous quasars within the first billion years of the Universe. The first massive black holes must therefore have formed around the time the first stars and galaxies formed. Dynamical evidence also indicates that black holes with masses of millions to billions of solar masses ordinarily dwell in the centers of today's galaxies. Massive black holes populate galaxy centers today, and shone as quasars in the past; the quiescent black holes that we detect now in nearby bulges are the dormant remnants of this fiery past. In this review we report on basic, but critical, questions regarding the cosmological significance of massive black holes. What physical mechanisms lead to the formation of the first massive black holes? How massive were the initial massive black hole seeds? When and where did they form? How is the growth of black holes linked to that of their host galaxy? Answers to most of these questions are work in progress, in the spirit of these Reports on Progress in Physics.

Assessing inflow rates in atomic cooling haloes: implications for direct collapse black holes

“…A detailed discussion of these mechanisms is given in reviews (Volonteri 2010;Volonteri & Bellovary 2012;Haiman 2012), and we summarize here the main features of relevance for this investigation. The particular direct collapse scenario we address here requires the presence of large accretion rates of about ≥ 0.01 − 0.1 M ⊙ /yr (Begelman 2010;Hosokawa et al 2013;Schleicher et al 2013;Ferrara et al 2014).…”

“…Various models for the formation of supermassive black hole seeds have been proposed (Rees 1984;Volonteri 2010;Volonteri & Bellovary 2012;Haiman 2012). One potential pathway is the collapse of a primordial, i.e., metal-free, "normal" star into a stellar-mass black hole.…”

Initial mass function of intermediate-mass black hole seeds

“…Along with the formation of first stars (Bromm & Yoshida 2011), the appearance of black holes (Volonteri & Bellovary 2012) is one of the most remarkable events occurring well within the first cosmic billion year (redshift z > ∼ 6). These two types of astrophysical objects likely had a very strong impact during cosmic evolution (Loeb et al 2008;Petri et al 2012;Park & Ricotti 2012;Jeon et al 2012;Tanaka et al 2012;Maiolino et al 2012;Valiante et al 2012) due to their radiative and mechanical energy/momentum injection in the surrounding interstellar medium of the host galaxy and into the intergalactic medium, thus drastically changing the subsequent galaxy formation history.…”

Simulating the growth of intermediate-mass black holes

“…dark matter structures with virial temperatures Tvir < ∼ 10 4 K and total masses M h < ∼ 10 8 M . The concurrent formation of the first black holes (Bellovary et al 2011;Volonteri & Bellovary 2012;Agarwal et al 2013, see Haiman 2013 for an updated review), as a final product of the evolution of the first massive stars, represents a second key event during the same cosmic epoch. The appearance of these classes of objects likely had a very strong impact on both the interstellar and the intergalactic medium, due to their radiative and mechanical feedback (Park & Ricotti 2011;Petri et al 2012;Park & Ricotti 2012;Jeon et al 2012;Tanaka et al 2012;Maiolino et al 2012;Park & Ricotti 2013;Nakauchi et al 2014).…”