1999/09/09 by Mark Lacy, Susan E. Ridgway, Susan Ridgway +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1016/s1387-6473(01)00182-8
published as New Astron.Rev. 46 (2002) 211-214 · 6 pages, 2 figures. To appear in "Lifecycles of Radio Galaxies", ed J. Biretta et al., New Astronomy Reviews
arxiv created 1999/09/09 · openalex publication_date 2002/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The most massive black holes lie in the most massive elliptical galaxies, and at low-z all radio-loud AGNs lie in giant ellipticals. This strongly suggests a link between radio-loudness and black hole mass. We argue that the increase in the radio-loud fraction with AGN luminosity in optically-selected quasar samples is consistent with this picture. We also use the ratio of black holes today to quasars at z~2 to conclude that the most bolometrically-luminous AGN, either radio-loud or radio quiet, are constrained to have lifetimes <~108 yr. If radio sources are associated with black holes of >~109 Msun at all redshifts, then the same lifetime constraint applies to all radio sources with luminosities above L5GHz ~ 1024 W/Hz/sr.