The slimming effect of advection on black-hole accretion flows

Abstract

At super-Eddington rates accretion flows onto black holes have been described as slim (aspect ratio $H/R\lesssim 1$) or thick (H/R >1) discs, also known as tori or (Polish) doughnuts. The relation between the two descriptions has never been established, but it was commonly believed that at sufficiently high accretion rates slim discs inflate, becoming thick. We wish to establish under what conditions slim accretion flows become thick. We use analytical equations, numerical 1+1 schemes, and numerical radiative MHD codes to describe and compare various accretion flow models at very high accretion rates.We find that the dominant effect of advection at high accretion rates precludes slim discs becoming thick. At super-Eddington rates accretion flows around black holes can always be considered slim rather than thick.

8 pages, 5 figures. Astronomy & Astrophysics, in press

References in corpus (15)

• General Relativistic Hydrodynamic Simulation of Accretion Flow from a Stellar Tidal Disruption
• The Nature of SS433 and the Ultraluminous X-ray Sources
• Masses, Beaming and Eddington Ratios in Ultraluminous X-ray Sources
• Three-dimensional simulations of super-critical black hole accretion disks --- luminosities, photon trapping and variability
• Global simulations of axisymmetric radiative black hole accretion disks in general relativity with a sub-grid magnetic dynamo
• Powerful radiative jets in super-critical accretion disks around non-spinning black holes
• Slim disks around Kerr black holes revisited
• Magnetized Tori around Kerr Black Holes: Analytic Solutions with a Toroidal Magnetic Field
• Energy flows in thick accretion disks and their consequences for black hole feedback
• Numerical Simulations of Optically Thick Accretion onto a Black Hole - II. Rotating Flow
• An ultraluminous nascent millisecond pulsar
• Radiation Pressure-supported Accretion Disks: Vertical Structure, Energy Advection, and Convective Stability
• HLX-1 may be an SS433 system
• X-ray Transients: Hyper- or Hypo-Luminous?
• On the Eddington limit for relativistic accretion discs

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