NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
An Accretion Model for the Growth of the Central Black Holes Associated with Ionization Instability in QuasarsA possible accretion model associated with the ionization instability of quasar disks is proposed to address the growth of the central black hole (BH) harbored in the host galaxy. The evolution of quasars in cosmic time is assumed to change from a highly active state to a quiescent state triggered by the S-shaped ionization instability of the quasar accretion disk. For a given external mass transfer rate supplied by the quasar host galaxy, ionization instability can modify the accretion rate in the disk and separate the accretion flows of the disk into three different phases, like an S-shape. We suggest that the bright quasars observed today are those quasars with disks in the upper branch of the S-shaped instability, and the faint or 'dormant' quasars are simply these systems in the lower branch. The middle branch is the transition state, which is unstable. We assume the quasar disk evolves according to the advection-dominated inflow-outflow solution (ADIOS) configuration in the stable lower branch of the S-shaped instability, and the Eddington accretion rate is used to constrain the accretion rate in the highly active phase. The mass ratio between a BH and its host galactic bulge is a natural consequence of an ADIOS. Our model also demonstrates that a seed BH approx. 2 x 10(exp 6) solar masses similar to those found in spiral galaxies today is needed to produce a BH with a final mass of approx. 2 x 10(exp 8) solar masses.
Document ID
20040073168
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Lu, Y.
(Rutgers Univ. Piscataway, NJ, United States)
Cheng, K. S.
(Yunnan Univ. Kunming, China)
Zhang, S. N.
Date Acquired
August 21, 2013
Publication Date
June 1, 2003
Publication Information
Publication: Astrophysical Journal
Publisher: American Astronomical Society
Volume: 590
Issue: 1
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: NAG5-7927
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available