A Practical Guide to the Massive Black Hole Cosmic History

Abstract

I review our current understanding of massive black hole (MBH) formation and evolution along the cosmic history. After a brief introductory overview of the relevance of MBHs in the hierarchical structure formation paradigm, I discuss the main viable channels for seed BH formation at high redshift and for their subsequent mass growth and spin evolution. The emerging hierarchical picture, where MBHs grow through merger triggered accretion episodes, acquiring their mass while shining as quasars, is overall robust, but too simplistic to explain the diversity observed in MBH phenomenology. I briefly discuss which future observations will help to shed light on the MBH cosmic history in the near future, paying particular attention to the upcoming gravitational wave window.

Low-frequency gravitational-wave science with eLISA/NGO

“…MBHs may be born as small seeds (10 2 -10 3 M ) from the core collapse of the first generation of 'Pop III' stars formed from gas clouds in light halos at z ∼ 15-20 [54,53]; or as large seeds (10 3 -10 5 M ) from the collapse of very massive quasi-stars formed in much heavier halos at z ∼ 10-15 [55,56]; or by runaway collisions in star clusters [57]; or again by direct gas collapse in mergers [58] (see [59,60] and references therein). The seeds then evolve over cosmic time through intermittent, copious accretion and through mergers with other MBHs after the merger of their galaxies.…”

Search for gravitational radiation from intermediate mass black hole binaries in data from the second LIGO-Virgo joint science run

“…Although no conclusive detections have been made to date, intermediate mass black holes are very intriguing astrophysical objects, with growing observational and theoretical evidence for their existence [1,2]. Their discovery would be a major breakthrough in our understanding of massive black hole formation [3,4], stellar-cluster evolution [5][6][7][8][9][10], and hyper/ultraluminous x-ray sources [11][12][13][14][15][16][17]. Coalescing intermediate mass black hole binaries (IMBHBs) are also the strongest candidate gravitational-wave (GW) sources accessible to ground-based interferometric detectors such as LIGO and Virgo [18,19].…”

The Tidal Disruption of Stars by Supermassive Black Holes

“…Many different mechanisms have been proposed for the formation of SMBH seeds (Sesana 2012), of which three stand out as particularly promising:…”