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On the evolution of the black‐hole/spheroid mass ratio
Author(s) -
Mclure R. J.,
Jarvis M. J.,
Targett T. A.,
Dunlop J. S.,
Best P. N.
Publication year - 2006
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200510509
Subject(s) - physics , supermassive black hole , astrophysics , redshift , black hole (networking) , galaxy , stellar mass , spheroid , quasar , mass ratio , virial theorem , intermediate mass black hole , population , astronomy , star formation , computer network , routing protocol , biochemistry , routing (electronic design automation) , chemistry , demography , sociology , computer science , in vitro , link state routing protocol
We present the results of a study which uses the 3CRR sample of radio‐loud active galactic nuclei (AGN) to investigate the evolution of the black‐hole:spheroid relation in the most massive early‐type galaxies from 0 < z < 2. Radioloud unification is exploited to obtain virial (line‐width) black‐hole mass estimates from the 3CRR quasars, and stellar mass estimates from the 3CRR radio galaxies, thereby providing black‐hole and stellar mass estimates for a single population of early‐type galaxies. At low redshift ( z < 1) the 3CRR sample is consistent with a black‐hole:spheroid ratio of M bh / M sph ≃ 0.002, in good agreement with that observed locally for quiescent galaxies of similar stellar mass ( M sph ≃ 5 × 10 11 M ⊙ ). However, over the redshift interval 0 < z < 2 the 3CRR black‐hole:spheroid ratio is found to evolve as M bh / M sph ∝ (1 + z ) 2.07±0.76 , reaching M bh / M sph ≃ 0.008 by redshift z ≃ 2. This evolution is found to be inconsistent with the local black‐hole:spheroid ratio remaining constant at a moderately significant level (98%). If confirmed, the detection of evolution in the 3CRR black‐hole:spheroid mass ratio further strengthens the evidence that, at least for massive early‐type galaxies, the growth of the central supermassive black hole may be completed before that of the host spheroid. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)