Results 231 to 240 of about 609 (248)
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Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 2000
Highly collimated jets are associated with young stellar objects of all masses. They are also prevalent in microquasars and a variety of active galactic nuclei. Common to all of these systems is the presence of accretion discs around central objects, be they young stars, compact objects, or black holes.
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Highly collimated jets are associated with young stellar objects of all masses. They are also prevalent in microquasars and a variety of active galactic nuclei. Common to all of these systems is the presence of accretion discs around central objects, be they young stars, compact objects, or black holes.
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1992
The amount of literature on accretion discs is now vast and growing. Accretion discs (and here I include all thin, centrifugally supported discs, whether gaseous or not) can be found in a wide range of astrophysical models including planetary rings, the presolar nebular, star formation, binary stars, galaxies and active galactic nuclei.
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The amount of literature on accretion discs is now vast and growing. Accretion discs (and here I include all thin, centrifugally supported discs, whether gaseous or not) can be found in a wide range of astrophysical models including planetary rings, the presolar nebular, star formation, binary stars, galaxies and active galactic nuclei.
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Accretion Discs in Astrophysics
Annual Review of Astronomy and Astrophysics, 1981If we put a particle in a circular orbit around a central gravitating body, it will stay in that orbit. If we then extract energy and angular momentum from the particle we may allow it to spiral slowly inwards. The amount of energy that can be extracted by such a process is equal to the binding energy of the innermost accessible orbit.
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Advances in Space Research, 1986
Abstract Based on large amount of observational data in the field of high energy astrophysics, and namely X- and Gamma-ray data, it is considered that most of the discrete sources are non-stationary. One of the mechanisms describing this phenomenon is the non-stationary disc accretion, of geometrically thin disc.
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Abstract Based on large amount of observational data in the field of high energy astrophysics, and namely X- and Gamma-ray data, it is considered that most of the discrete sources are non-stationary. One of the mechanisms describing this phenomenon is the non-stationary disc accretion, of geometrically thin disc.
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Modelling magnetised accretion discs
2008Some recent results are reviewed that lead us now to believe that accretion discs are basically always magnetised. The main components are Balbus-Hawley and Parker instabilities on the one hand and a dynamo process on the other. A mechanical model for the Balbus-Hawley instability is presented and analysed quantitatively.
A. Brandenburg, C. Campbell
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2018
There is observational evidence that accretion discs in interacting binaries have wind flows emanating from their surfaces, and that the flow tends to become collimated parallel to the disc rotation axis. It is known that a differentially rotating, turbulent disc can have a large-scale magnetic field generated by dynamo action.
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There is observational evidence that accretion discs in interacting binaries have wind flows emanating from their surfaces, and that the flow tends to become collimated parallel to the disc rotation axis. It is known that a differentially rotating, turbulent disc can have a large-scale magnetic field generated by dynamo action.
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Relativistic Twisted Accretion Disc
2018A twisted disc forms around a rotating black hole each time when the disc outskirts are not aligned with the black hole’s equatorial plane. We derive equations describing the evolution of the shape of twisted discs and perturbations of density and velocity necessarily arising in such a disc.
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Magneto-viscous accretion discs
2008Magnetic models of accretion discs are presented and discussed. The magnetic field is generated and maintained in the disc by a dynamo mechanism. The relative magnitudes of the azimuthal viscous and magnetic forces depend on the diffusion mechanism considered.
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Accretion Discs in Astrophysics
Abstract Accretion discs are those vast swirling discs of gas that form around young and dying stars. They provide the essential mechanism by which mass accretes onto a star, a process that relies crucially on turbulent diffusion within the disc.openaire +1 more source
Relativistic Standard Accretion Disc
2018In this chapter we present a model of a standard accretion disc around a rotating black hole taking general relativity effects into full account. This model was first described in the paper by Novikov and Thorne (Black holes (Les Astres Occlus). Gordon and Breach, New York, 1973) and has since then been used in many studies to obtain convincing ...
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