Related papers: A class of self-gravitating, magnetized accretion …
Motivated by indirect observational evidence for strongly magnetized accretion discs around black holes, and the novel theoretical properties of such solutions, we investigate how a strong magnetization state can develop and persist. To…
We present 3D magnetohydrodynamic (MHD) numerical simulations of the evolution of self--gravitating and weakly magnetized disks with an adiabatic equation of state. Such disks are subject to the development of both the magnetorotational and…
We present a study of instabilities occuring in thick magnetized accretion disks. We calculate the growth rates of these instabilities and characterise precisely the contribution of the magneto-rotational and the convective mechanism. All…
Qualitative arguments are presented to demonstrate that the energy density of magnetic fields in matter accreting onto a black hole inside the marginally stable orbit is automatically comparable to the rest-mass energy density of the…
The vertical structure of black hole accretion disks in which radiation dominates the total pressure is investigated using a three-dimensional radiation-MHD calculation. The domain is a small patch of disk centered 100 Schwarzschild radii…
The exact superposition of a central static black hole with surrounding thin disk in presence of a magnetic field is investigated. We consider two models of disk, one of infinite extension based on a Kuzmin-Chazy-Curzon metric and other…
We investigate the stability of partially ionised, differentially rotating, diffusive disc threaded by both azimuthal and vertical magnetic field. The general stability criterion of such a disc in the presence of axisymmetric fluctuations…
An analysis of instability dynamics in a stochastic magnetic field is presented for the tractable case of the resistive interchange. Externally prescribed static magnetic perturbations convert the eigenmode problem to a stochastic…
Observations are providing increasingly detailed quantitative information about the accretion flows that power such high energy systems as X-ray binaries and active galactic nuclei. Analytic models of such systems must rely on assumptions…
We present a set of new characteristic frequencies associated with accretion disks around compact objects. These frequencies arise from persistent rotating patterns in the disk that are finite in radial extent and driven purely by the…
Semi-analytic models of self-gravitating discs often approximate the angular momentum transport generated by the gravitational instability using the phenomenology of viscosity. This allows the employment of the standard viscous evolution…
We have performed systemmatic local linear stability analysis on a radially stratified infinite self-gravitating cylinder of rotating plasma under the influence of magnetic field. In order to render the system analytically tractable, we…
The self-similar equilibrium models of self-gravitating, rotating, isothermal systems are investigated analytically. In these models the rotation velocity is constant and the density varies as $\frac{f(\theta, \phi)}{r^2}$, where $r$ and…
We propose that the strength of angular momentum transport in accretion discs threaded by net vertical magnetic field is determined by a self-regulation mechanism: the magnetorotational instability (MRI) grows until its own turbulent…
An investigation is made of disk accretion of matter onto a rotating star with an aligned dipole magnetic field. A new aspect of this work is that when the angular velocity of the star and disk differ substantially we argue that the $\bf B$…
Magnetic excitations of single atoms on surfaces have been widely studied experimentally in the past decade. Lately, systems with unprecedented magnetic stability started to emerge. Here, we present a general theoretical investigation of…
The properties of super-Eddington accretion disks exhibit substantial distinctions from the sub- Eddington ones. In this paper, we investigate the accretion process of a magnetized neutron star (NS) surrounded by a super-Eddington disk. By…
The exact time-dependent solution is obtained for a magnetic field growth during a spherically symmetric accretion into a black hole (BH) with a Schwarzschild metric. Magnetic field is increasing with time, changing from the initially…
The groundstate energy and binding energy of an exciton, confined in a^M quantum disk, are calculated as a function of an external magnetic field. The confinement potential is a hard wall of finite height. The diamagnetic shift is…
Accretion disks and astrophysical jets are used to model many active astrophysical objects, viz., young stars, relativistic stars, and active galactic nuclei. In this paper we present self-consistent time-dependent simulations of supersonic…