Physical constraints on the sizes of dense clouds in the central magnetospheres of Active Galactic Nuclei

Abstract

The range of microphysical and global dynamical timescales in the central regions of Active Galactic Nuclei (AGN) is sufficiently wide to permit the existence of multiphase structure. In particular, very dense, cool clouds can coexist with a hot, magnetically-dominated medium and can thereby efficiently reprocess the continuum radiation generated in this primary source region. The strong dynamical forces in this central magnetosphere can give rise to extremely small clouds. Microphysical processes then determine whether such clouds can indeed survive, in spite of their extremely contrasting properties relative to the surrounding environment, for long enough to produce potentially observable thermal reprocessing signatures. We examine specific physical constraints on the thicknesses of such reprocessing clouds. Our results are plotted to show the range of conditions that is representative of the central regions of AGN. We find a parameter subspace in the extreme high density regime for which the effects of microphysical diffusion processes can be overcome and for which cool gas can maintain pressure equilibrium with the ambient magnetosphere.

9 pages, LaTeX type, 2 postscript figures, uses rotate.sty and epsf.sty, accepted for publication in MNRAS

Cited by in corpus (17)

• How the X-ray spectrum of a Narrow-Line Seyfert 1 galaxy may be reflection dominated
• The jet feedback mechanism (jfm) in stars, galaxies and clusters
• XMM-Newton discovery of a sharp spectral feature at ~7 keV in the Narrow-Line Seyfert 1 galaxy 1H 0707-495
• Hydrodynamic Interaction of Strong Shocks with Inhomogeneous Media - I: Adiabatic Case
• The UV peak in Active Galactic Nuclei : a false continuum from blurred reflection ?
• A New Equilibrium for Accretion Disks Around Black Holes
• Clumpy accretion onto black holes. I. Clumpy-ADAF structure and radiation
• Comparisons of various model fits to the Iron line profile in MCG-6-30-15
• A quasi-spherical inner accretion flow in Seyfert galaxies ?
• Reprocessed emission line profiles from dense clouds in geometrically thick accretion engines
• Does the Iron K${}_{\alpha }$ Line of Active Galactic Nuclei Arise from the Cerenkov Line-like Radiation?
• Broad-line Region Clouds orbiting an AGN sample
• Reprocessing of radiation by multi-phase gas in Low Luminosity Accretion Flows
• Dynamics of clumps embedded in a hot accretion flow with toroidal magnetic field
• A Monte Carlo Study of the Spectra from Inhomogeneous Accretion Flow
• The width-flux relation of the broad iron line during the state transition of the black hole X-ray binaries
• Thermal Conduction in Clumpy Disks and BLR clouds