Open AccessMassive black hole remnants of the first stars – I. Abundance in present‐day galactic haloes
Author(s) -
Islam Ranty R.,
Taylor James E.,
Silk Joseph
Publication year - 2004
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.1365-2966.2004.08201.x
Subject(s) - physics , astrophysics , supermassive black hole , astronomy , galaxy , bulge , accretion (finance) , dark matter , black hole (networking) , galactic center , milky way , intermediate mass black hole , population , computer network , routing protocol , routing (electronic design automation) , demography , sociology , computer science , link state routing protocol
ABSTRACT We investigate the possibility that present‐day galaxies and their dark matter haloes contain a population of massive black holes (MBHs) that form by hierarchical merging of the black hole remnants of the first stars in the Universe. Some of the MBHs may be large enough or close enough to the centre of the galactic host that they merge within a Hubble time. We estimate to what extent this process could contribute to the mass of the supermassive black holes (SMBHs) observed in galactic centres today. The relation between SMBH and galactic bulge mass in our model displays the same slope as that found in observations. Many MBHs will not reach the centre of the host halo, however, but continue to orbit within it. In doing so MBHs may remain associated with remnants of the satellite halo systems of which they were previously a part. Using a semi‐analytical approach that explicitly accounts for dynamical friction, tidal disruption and encounters with galactic discs, we follow the hierarchical merging of MBH systems and their subsequent dynamical evolution inside the respective host haloes. We predict the mass and abundance of MBHs in present‐day galactic haloes, and also estimate the MBH mass accretion rates as well as bolometric luminosities for two accretion scenarios. MBHs that have not undergone recent merging will retain associated dark matter cusps that were enhanced by black hole accretion growth, and may be possible sources of gamma‐rays via neutralino annihilations.