Accretion disk models for QSOs and active galactic nuclei - The role of magnetic viscosity

Abstract

view Abstract Citations (177) References (34) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Accretion disk models for QSOs and active galactic nuclei - The role of magnetic viscosity Sakimoto, P. J. ; Coroniti, F. V. Abstract The inner regions of standard accretion disk models are known to be thermally unstable, and when scaled to quasar black hole masses, optically thin. Alternative accretion disk models are constructed under the assumption of a purely magnetic viscosity in the limiting cases of equipartition of gas and magnetic pressures and global flux conservation. The inner regions of these models are considerably denser than the standard model and therefore remain optically thick in all regions. The equipartition model is thermally stable throughout, while flux conservation leads to a localized thermal instability at the gas pressure/radiation pressure boundary and marginal stability as the radial distance approaches zero. The outer regions of quasar scaled accretion disks are strongly self-gravitating, leading to a vertical scale height which is smaller than that found in the inner region. Most of the outer region is gravitationally unstable, implying that the outer parts of galactic nuclei accretion disks are populated by dense self-gravitating gas clouds or possibly by stars. Publication: The Astrophysical Journal Pub Date: July 1981 DOI: 10.1086/159005 Bibcode: 1981ApJ...247...19S Keywords: Active Galactic Nuclei; Black Holes (Astronomy); Magnetic Properties; Quasars; Stellar Mass Accretion; Viscosity; Black Body Radiation; Gas Pressure; Mass Ratios; Stellar Models; Thermal Instability; X Ray Sources; Astrophysics full text sources ADS |