Open AccessThe fraction of galaxies that contain active nuclei and their accretion rates
Author(s) -
Page M.J.
Publication year - 2001
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 - 10.1046/j.1365-8711.2001.04919.x
Subject(s) - physics , astrophysics , galaxy , luminosity function , luminous infrared galaxy , accretion (finance) , luminosity , active galactic nucleus , eddington luminosity , astronomy , radio galaxy , elliptical galaxy
We investigate the relationship between the present‐day optical luminosity function of galaxies and the X‐ray luminosity function of Seyfert 1s to determine the fraction of galaxies that host Seyfert 1 nuclei and their Eddington ratios. The local type 1 active galactic nuclei (AGN) X‐ray luminosity function is well reproduced if ∼1 per cent of all galaxies are type 1 Seyferts which have Eddington ratios of ∼10 −3 . However, in such a model the X‐ray luminosity function is completely dominated by AGN in E and S0 galaxies, contrary to the observed mix of Seyfert host galaxies. To obtain a plausible mix of AGN host galaxy morphologies requires that the most massive black holes in E and S0 galaxies accrete with lower Eddington ratios, or have a lower incidence of Seyfert activity, than the central black holes of later‐type galaxies.