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Relativistic Accretion Disk Models of High-State Black Hole X-Ray Binary Spectra
We present calculations of non-LTE, relativistic accretion disk models applicable to the high/soft state of black hole X-ray binaries. We include the effects of thermal Comptonization and bound-free
Intrinsic disc emission and the soft X‐ray excess in active galactic nuclei
Narrow-line Seyfert 1 (NLS1) galaxies have low-mass black holes and mass accretion rates close to (or exceeding) Eddington, so a standard blackbody accretion disc should peak in the extreme
Simultaneous EUVE/ASCA/RXTE Observations of NGC 5548
We present simultaneous observations by EUVE, ASCA, and RXTE of the type?1 Seyfert galaxy NGC?5548. These data indicate that variations in the EUV emission (at ~0.2 keV) appear to lead similar
The Kozai Mechanism and the Evolution of Binary Supermassive Black Holes
We consider the dynamical evolution of bound, hierarchical triples of supermassive black holes that might be formed in the nuclei of galaxies undergoing sequential mergers. The tidal force of the
The Ultraviolet and Optical Continuum Emission in Active Galactic Nuclei: The Status of Accretion Disks
A fundamental component of models of active galactic nuclei (AGNs) is an accretion disk around a supermassive black hole. However, the nature of this accretion disk is not well understood, and
A spectral decomposition of the variable optical, ultraviolet and X-ray continuum of NGC 5548
We present an analysis and decomposition of the broad-band optical/UV/X-ray/γ-ray spectrum of the Seyfert 1 galaxy NGC 5548. The spectrum consists of an average of simultaneous optical/IUE/Ginga
The UV Continuum of Quasars: Models and SDSS Spectral Slopes
We measure long (2200-4000 A) and short (1450-2200 A) wavelength spectral slopes α (Fν να) for quasar spectra from the Sloan Digital Sky Survey. The long- and short-wavelength slopes are computed
Global General Relativistic Magnetohydrodynamic Simulation of a Tilted Black Hole Accretion Disk
This paper presents a continuation of our efforts to numerically study accretion disks that are misaligned (tilted) with respect to the rotation axis of a Kerr black hole. Here we present results of
Radiation-Dominated Disks are Thermally Stable
When the accretion rate is more than a small fraction of Eddington, the inner regions of accretion disks around black holes are expected to be radiation dominated. However, in the α-model, these
We extend the analysis of axisymmetric magnetic shear instabilities from ideal magnetohydrodynamic (MHD) flows to weakly ionized plasmas with coupling between ions and neutrals caused by collisions,