Open AccessBlack hole growth in hierarchical galaxy formation
Author(s) -
Malbon Rowena K.,
Baugh C. M.,
Frenk C. S.,
Lacey C. G.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2007.12317.x
Subject(s) - physics , astrophysics , black hole (networking) , redshift , intermediate mass black hole , supermassive black hole , stellar black hole , binary black hole , quasar , bulge , astronomy , galaxy , spin flip , galaxy formation and evolution , gravitational wave , computer network , routing protocol , routing (electronic design automation) , computer science , link state routing protocol
We incorporate a model for black hole growth during galaxy mergers into the semi‐analytical galaxy formation model based on ΛCDM proposed by Baugh et al. Our black hole model has one free parameter, which we set by matching the observed zero‐point of the local correlation between black hole mass and bulge luminosity. We present predictions for the evolution with redshift of the relationships between black hole mass and bulge properties. Our simulations reproduce the evolution of the optical luminosity function of quasars. We study the demographics of the black hole population and address the issue of how black holes acquire their mass. We find that the direct accretion of cold gas during starbursts is an important growth mechanism for lower mass black holes and at high redshift. On the other hand, the re‐assembly of pre‐existing black hole mass into larger units via merging dominates the growth of more massive black holes at low redshift. This prediction could be tested by future gravitational wave experiments. As redshift decreases, progressively less massive black holes have the highest fractional growth rates, in line with recent claims of ‘downsizing’ in quasar activity.