Supermassive black holes (SMBHs) of 109-1010Mâwere already in place ~13 Gyr ago, at z > 6. Super-Eddington growth of low-mass BH seeds (~100Mâ) or less extreme accretion on to~105Mâseeds have been recently considered as the main viable routes to these SMBHs. Here, we study the statistics of these SMBH progenitors at z ~ 6. The growth of low- and high-mass seeds and their host galaxies are consistently followed using the cosmological data constrained model GAMETE/QSODUST, which reproduces the observed properties of high-z quasars, like SDSS J1148+5251.We show that both seed formation channels can be in action over a similar redshift range 15 < z < 18 and are found in dark matter haloes with comparable mass, ~5 Ã 107Mâ. However, as long as the systems evolve in isolation (i.e. no mergers occur), noticeable differences in their properties emerge: At z â¥ 10 galaxies hosting high-mass seeds have smaller stellar mass and metallicity, the BHs accrete gas at higher rates and star formation proceeds less efficiently than in low-mass seeds hosts. At z < 10 these differences are progressively erased, as the systems experience minor or major mergers and every trace of the BH origin gets lost.
|Titolo:||Chasing the observational signatures of seed black holes at z > 7: Candidate statistics|
|Data di pubblicazione:||2018|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1093/mnras/stx3028|
|Parole Chiave:||Galaxies: active; Quasars: general; Quasars: supermassive black holes; Stars: black holes; Astronomy and Astrophysics; Space and Planetary Science|
|Appare nelle tipologie:||1.1 Articolo in rivista|