Open AccessEvolution in the black hole mass–bulge mass relation: a theoretical perspective
Author(s) -
Croton Darren J.
Publication year - 2006
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.1365-2966.2006.10429.x
Subject(s) - physics , astrophysics , bulge , supermassive black hole , black hole (networking) , galaxy formation and evolution , astronomy , galaxy , galaxy merger , cold dark matter , population , redshift , intermediate mass black hole , computer network , routing protocol , routing (electronic design automation) , demography , sociology , computer science , link state routing protocol
We explore the growth of supermassive black holes and host galaxy bulges in the galaxy population using the Millennium Run Λ cold dark matter (ΛCDM) simulation coupled with a model of galaxy formation. We find that, if galaxy mergers are the primary drivers for both bulge and black hole growth, then in the simplest picture one should expect the m BH – m bulge relation to evolve with redshift, with a larger black hole mass associated with a given bulge mass at earlier times relative to the present day. This result is independent of an evolving cold gas fraction in the galaxy population. The evolution arises from the disruption of galactic discs during mergers that make a larger fractional mass contribution to bulges at low redshift than at earlier epochs. There is no comparable growth mode for the black hole population. Thus, this effect produces evolution in the m BH – m bulge relation that is driven by bulge mass growth and not by black holes.