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Rossi X‐Ray Timing Explorer Observation of Cygnus X‐1. II. Timing Analysis
We present timing analysis for a Rossi X-Ray Timing Explorer (RXTE) observation of Cygnus X-1 in its hard/low state. This was the first RXTE observation of Cyg X-1 taken after it transited back to… Expand
Massive black hole binaries in active galactic nuclei
Most theoretical discussions of active galactic nuclei (including quasars) attribute their energy production either to an accreting black hole or to a precursor stage—for instance a dense star… Expand
On the fate of gas accreting at a low rate on to a black hole
Gas supplied conservatively to a black hole at rates well below the Eddington rate may not be able to radiate effectively and the net energy flux, including the energy transported by the viscous… Expand
Ion-supported tori and the origin of radio jets
While apparently supplying tremendous power to their extended radio-emitting regions, the nuclei of most radio galaxies emit little detectable radiation. It is proposed that at the centre of each is… Expand
Comptonization of Diffuse Ambient Radiation by a Relativistic Jet: The Source of Gamma Rays from Blazars?
Recent Energy Gamma Ray Experiment Telescope (EGRET) observations of blazars have revealed strong, variable gamma-ray fluxes with no signatures of gamma-ray absorption by pair production. This… Expand
Molecular tori in Seyfert galaxies - Feeding the monster and hiding it
The principal properties of the tori of gas which surround Seyfert nuclei are discussed. The internal state of the clouds and their size distribution function are examined, and it is shown that the… Expand
XMM-EPIC observation of MCG-6-30-15: direct evidence for the extraction of energy from a spinning black hole?
We present XMM-Newton European Photon Imaging Camera (EPIC) observations of the bright Seyfert 1 galaxy MCG 6-30-15, focusing on the broad Fe Kline at � 6keV and the associated reflection continuum,… Expand
Evolution of supermassive stars as a pathway to black hole formation
- M. Begelman
- 22 October 2009
Supermassive stars, with masses ≳10 6 M ⊙ , are possible progenitors of supermassive black holes in galactic nuclei. Because of their short nuclear burning time-scales, such objects can be formed… Expand
Hydrodynamical non-radiative accretion flows in two dimensions
Two-dimensional (axially symmetric) numerical hydrodynamical calculations of accretion flows that cannot cool through emission of radiation are presented. The calculations begin from an equilibrium… Expand
Compton heated winds and coronae above accretion disks. I. Dynamics
X rays emitted in the inner part of an accretion disk system can heat the surface of the disk farther out, producing a corona and possibly driving off a strong wind. The dynamics of Compton-heated… Expand