Results 11 to 20 of about 52,369 (293)
Hydrodynamical activity in thin accretion disks
New Astronomy Reviews, 2008 An asymptotic treatment of thin accretion disks, introduced by Klu\'zniak & Kita (2000) for a steady-state disk flow, is extended to a time-dependent problem. Transient growth of axisymmetric disturbances is analytically shown to occur on the global disk
Afshordi +54 more
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RINGED ACCRETION DISKS: INSTABILITIES [PDF]
The Astrophysical Journal Supplement Series, 2016 ABSTRACT We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or
Pugliese, D., Stuchlík, Z.
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Astrophysics and Space Science, 1999 LaTex, 6 pages with 1 postscript and 1 jpg figure, and 1 postscript table, To appear in the proc. of the Ringberg workshop on "Ultraluminous Galaxies: Monsters or Babies" (Ringberg castle, Sept.
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Fragmentation of Massive Protostellar Disks [PDF]
, 2006 We examine whether massive-star accretion disks are likely to fragment due to self-gravity. Rapid accretion and high angular momentum push these disks toward fragmentation, whereas viscous heating and the high protostellar luminosity stabilize them.
Adams +59 more
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Accretion disk instabilities [PDF]
International Astronomical Union Colloquium, 1986 In this article we discuss two instabilities of stationary accretion disks which lead to an understanding of observed light variations in accretion disk systems, the dwarf novae and the rapid burster MXB 17030-335. The accretion disks in these systems avoid instability at the cost of stationarity and perform stable cycles in which sudden changes of the
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Accretion Disk Evolution [PDF]
International Astronomical Union Colloquium, 1987 AbstractThree aspects of mass transfer instability models of dwarf novae are examined. The hydrodynamic development of instabilities in the secondary are examined within Roche geometry and shown to extend at least a few degrees away from the line of centres.
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Accretion Disk Instabilities [PDF]
International Astronomical Union Colloquium, 1993 AbstractBasic properties of accretion disk instabilities are summarized. We first explain the standard disk model by Shakura and Sunyaev. In this model, the dominant sources of viscosity are assumed to be chaotic magnetic fields and turbulence in gas flow, and the magnitude of viscosity is prescribed by so-called a model. It is then possible to build a
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ACCRETION DISKS WITH A LARGE SCALE MAGNETIC FIELD AROUND BLACK HOLES
Acta Polytechnica, 2013 We consider accretion disks around black holes at high luminosity, and the problem of the formation of a large-scale magnetic field in such disks, taking into account the non-uniform vertical structure of the disk.
Gennady Bisnovatyi-Kogan +2 more
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The Astrophysical Journal, 2023 We present global 3D radiation magnetohydrodynamic simulations of accretion onto a 6.62 solar-mass black hole, with quasi-steady-state accretion rates reaching 0.016–0.9 times the critical accretion rate, which is defined as the accretion rate for ...
Jiahui Huang +5 more
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Nucleosynthesis in the Outflow from Gamma Ray Burst Accretion Disks [PDF]
, 2005 We examine the nucleosynthesis products that are produced in the outflow from rapidly accreting disks. We find that the type of element synthesis varies dramatically with the degree of neutrino trapping in the disk and therefore the accretion rate of the
G. C. McLaughlin +4 more
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