منابع مشابه
Stability of accretion discs threaded by a strong magnetic field
We study the stability of poloidal magnetic fields anchored in a thin accretion disc. The two-dimensional hydrodynamics in the disc plane is followed by a grid-based numerical simulation including the vertically integrated magnetic forces. The 3–dimensional magnetic field outside the disc is calculated in a potential field approximation from the magnetic flux density distribution in the disc. F...
متن کاملAccretion Discs with Strong Toroidal Magnetic Fields
Simulations and analytic arguments suggest that the turbulence driven by magnetorotational instability (MRI) in accretion discs can amplify the toroidal (azimuthal) component of the magnetic field to a point at which magnetic pressure exceeds the combined gas + radiation pressure in the disc. Arguing from the recent analysis by Pessah and Psaltis, and other MRI results in the literature, we con...
متن کاملStationary magnetic field configurations in accretion discs around neutron stars – the role of velocity and diffusivity
We report results from calculations investigating stationary magnetic field configurations in accretion discs around magnetised neutron stars. Our strategy is to start with a very simple model and then progressively improve it providing complementary insight into results obtained with large numerical simulations. In our first model, presented here, we work in the kinetic approximation and consi...
متن کاملModelling magnetised accretion discs
Some 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. Three-dimensional simulations are discussed, especially the resulting mag...
متن کاملSelf-gravitating accretion discs
— I review recent progresses in the dynamics and the evolution of self-gravitating accretion discs. Accretion discs are a fundamental component of several astrophysical systems on very diverse scales, and can be found around supermassive black holes in Active Galactic Nuclei (AGN), and also in our Galaxy around stellar mass compact objects and around young stars. Notwithstanding the specific di...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1994
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/267.2.235