2003/08/30 by Craig Tyler, Tyler, Craig, Brent Janus +3 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0309008
15 pages, submitted to ApJ
arxiv created 2003/08/30 · openalex publication_date 2003/08/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The high redshifts of the most distant known quasars, and the best estimates of their black hole masses, require that supermassive black holes (SMBHs) must have formed very early in history. Several mechanisms for creating and growing these holes have been proposed. Here we present an evaluation of the timescales needed for various critical processes in order to discriminate between the proposed scenarios. We find in particular that mergers alone are not able to grow the black holes at a sufficient rate. Accretion models offer a solution and we use accretion timescales to constrain the manner in which the black hole was first formed. This analysis implies, but does not require, the action of some unconventional process.