Related papers: The Hall effect in accretion flows
The evolution of a large-scale poloidal magnetic field in accretion discs is an important problem because of its role in the launching of jets and winds and in determining the intensity of turbulence. In this paper, we develop a formalism…
Taking advantage of the anomalous Hall effect, we electrically probe low-frequency magnetization fluctuations at room temperature in a thin ferromagnetic Pt/Co/AlO$_x$ layer stack with perpendicular magnetic anisotropy. We observe a strong…
We have explored the structure of hot flow bathed in a general large-scale magnetic field. The importance of outflow and thermal conduction on the self-similar structure of a hot accretion flows has been investigated. We consider the…
Accretion flows may produce profuse winds when they have positive specific energy. Winds deplete matter from the inner region of the disk and makes the inner region thinner, optically. Since there are fewer electrons in this region, it…
We present three-dimensional MHD simulations of rotating radiatively inefficient accretion flows onto black holes. In the simulations, we continuously inject magnetized matter into the computational domain near the outer boundary, and we…
We present a set of numerical simulations addressing the effects of magnetic field strength and orientation on the flow-driven formation of molecular clouds. Fields perpendicular to the flows sweeping up the cloud can efficiently prevent…
We present a linear analysis of the vertical structure and growth of the magnetorotational instability in stratified, weakly ionised accretion discs, such as protostellar and quiescent dwarf novae systems. The method includes the effects of…
We examine the effects of a hydrodynamical wind on advection dominated accretion flows with thermal conduction in the presence of a toroidal magnetic field under a self-similar treatment. The disk gas is assumed to be isothermal. For a…
We explore the global structure of the accretion flow around a Schwarzschild black hole where the accretion disc is threaded by toroidal magnetic fields. The accretion flow is optically thin and advection dominated. Synchrotron radiation is…
The partial ionization of the solar plasma causes several nonideal effects such as the ambipolar diffusion, the Hall effect, and the Biermann battery effect. Here we report on the first three-dimensional realistic simulations of solar local…
The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology or reconnect in highly conducting media. Recent progress in understanding fast…
These notes introduce and review some of the physical principles underlying the theory of astrophysical accretion, emphasizing the central roles of angular momentum transport, angular momentum loss, and radiative cooling in determining the…
The constraint imposed by magnetic helicity conservation on the alpha effect is considered for both magnetically and flow dominated self-organizing plasmas. Direct numerical simulations are presented for a dominant contribution to the alpha…
Non-ideal magnetohydrodynamic (MHD) processes -- namely Ohmic resistivity, ambipolar diffusion and the Hall effect -- modify the early stages of the star formation process and the surrounding environment. Collectively, they have been shown…
Effects of magnetic coupling (MC) of a rotating black hole (BH) with its surrounding accretion disk are discussed in detail in the following aspects: (i) The mapping relation between the angular coordinate on the BH horizon and the radial…
The Kelvin-Helmholtz instability is well known to be capable of converting well-ordered flows into more disordered, even turbulent, flows. As such it could represent a path by which the energy in, for example, bowshocks from stellar jets…
The turbulent diffusion tensor describing the evolution of the mean concentration of a passive scalar is investigated for non-helically forced turbulence in the presence of rotation or a magnetic field. With rotation, the Coriolis force…
As well known, magnetic fields in space are distributed very inhomogeneously. Some-times field distributions have forms of filaments with high magnetic field values. As many ob-servations show, such a filamentation takes place in convective…
We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting…
We present here the solutions of magnetized accretion flows on to a compact object with hard surface such as neutron stars. The magnetic field of the central star is assumed dipolar and the magnetic axis is assumed to be aligned with the…