Related papers: Magnetic Fields in Accretion Disks: A Review
We investigate the properties of a hot accretion flow bathed in a poloidal magnetic field. We consider an axisymmetric viscous resistive flow in the steady state configuration. We assume the dominant mechanism of energy dissipation is due…
The inward flow of matter through accretion disks is driven by MHD turbulence. Global general relativistic MHD simulations shed quantitative light on this process, revealing a number of aspects of accretion previously unrecognized. Among…
It is shown that a dynamo can operate in an Active Galactic Nuclei accretion disk due to the Keplerian shear and due to the helical motions of expanding and twisting plumes of plasma heated by many star passages through the disk. Each plume…
We show that the motion of the neutral masses in an accretion disk orbiting a black hole creates a general-relativistic magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near the accretion disk upward and…
Whenever in a classical accretion disk the thin disk approximation fails interior to a certain radius, a transition from Keplerian to radial infalling trajectories should occur. We show that this transition is actually expected to occur…
Current theoretical models for the outflows/jets from AGN, X-ray binaries and young stellar objects involve large-scale magnetic fields threading an underlying accretion disk. We suggest that such a disk is subjected to warping instability…
We use axisymmetric magnetohydrodynamic (MHD) simulations to investigate the launching and collimation of jets emerging from the disk-magnetosphere boundary of accreting magnetized stars. Our analysis shows that the matter flows into the…
Combined influence of rotation of a black hole and ambient magnetic fields creates conditions for powerful astrophysical processes of accretion and outflow of matter which are observed in many systems across the range of masses; from…
Aims: We determine the steady-state of an axisymmetric thin accretion disc with an internal dynamo around a magnetised star. Methods: Starting from the vertically integrated equations of magnetohydrodynamics we derive a single ordinary…
Large scale, strong magnetic fields are often evoked in black hole accretion flows, for jet launching in the low/hard state and to circumvent the thermal instability in the high/soft state. Here we show how these ideas are strongly…
In a series of our previous works, a model of radiatively inefficient accretion flows (RIAFs) in a global magnetic field (so called resistive RIAF model) has proved its ability to account for many physical processes taking place in such…
Magnetic fields surrounding black holes are responsible for various astrophysical phenomena related to accretion processes and relativistic jets. Depending on the source, the configuration of the field lines may differ significantly,…
Many, if not all, post AGB stellar systems swiftly transition from a spherical to a powerful aspherical pre-planetary nebula (pPNE) outflow phase before waning into a PNe. The pPNe outflows require engine rotational energy and a mechanism…
We consider the power of a relativistic jet accelerated by the magnetic field of an accretion disc. It is found that the power extracted from the disc is mainly determined by the field strength and configuration of the field far from the…
Jets and outflows are thought to be an integral part of accretion phenomena and are associated with a large variety of objects. In these systems, the interaction of magnetic fields with an accretion disk and/or a magnetized central object…
We present magnetohydrodynamic simulations of a resistive accretion disk continuously launching transmagnetosonic, collimated jets. We time-evolve the full set of magnetohydrodynamic equations, but neglect radiative losses in the energetics…
Magnetic fields are known to play a crucial role in the star formation process, particularly in the formation of jets and outflows from protostellar discs. The magnetic field structure in star forming regions is not always uniform and…
Hydromagnetic stresses in accretion discs have been the subject of intense theoretical research over the past one and a half decades. Most of the disc simulations have assumed a small initial magnetic field and studied the turbulence that…
Axisymmetric magnetohydrodynamic (MHD) simulations have been applied to investigate the interrelation of a central stellar magnetosphere and stellar wind with a surrounding magnetized disk outflow and how the overall formation of a large…
The strength and structure of the large-scale magnetic field in protoplanetary discs are still unknown, although they could have important consequences for the dynamics and evolution of the disc. Using a mean-field approach in which we…