Related papers: How does a Secular Instability Grow in a Hyperaccr…
In an incompressible flow, fluid density remains invariant along fluid element trajectories. This implies that the spatial distribution of non-interacting noninertial particles in such flows cannot develop density inhomogeneities beyond…
We investigate acceleration and propagation processes of high-energy particles inside hot accretion flows. The magnetorotational instability (MRI) creates turbulence inside accretion flows, which triggers magnetic reconnection and may…
We have used a model of magnetic accretion to investigate the accretion flows of magnetic cataclysmic variables. Numerical simulations demonstrate that four types of flow are possible: discs, streams, rings and propellers. The fundamental…
Numerical calculations and linear theory of radiation magnetohydrodynamic flows indicate that the photon bubble and magnetorotational instability (MRI) may produce large density inhomogeneities in radiation pressure supported media. We…
We present self-similar solutions for advection-dominated accretion flows with radial viscous force in the presence of outflows from the accretion flow or infall. The axisymmetric flow is treated in variables integrated over polar sections…
Tidal disruption events (TDEs) are believed to be an ideal laboratory for studying the evolution of accretion flow around a supermassive black hole (BH). In general, the mass feeding rate to the BH is suggested to be super-Eddington…
We present three-dimensional (3-D) hydrodynamical simulations of gas flows in the vicinity of an active galactic nucleus (AGN) powered by a precessing accretion disk. We consider the effects of the radiation force from such a disk on its…
We propose a model of the accretion flow onto a black hole consisting of the accretion disk with an accreting two-temperature corona. The model is based on assumptions about the radiative and conductive energy exchange between the two…
We numerically investigate the flow structure of periodic steady water waves of fixed relative mass flux propagating on rotational flows with piece-wise constant vorticity. We show that for wave solutions along the global bifurcation…
We investigate the 2D instability recently discussed by Gallet et al. (2010) and Ilin \& Morgulis (2013) which arises when a radial crossflow is imposed on a centrifugally-stable swirling flow. By finding a simpler rectilinear example of…
We present the results from axisymmetric time-dependent HD calculations of gas flows which are under the influence of gravity of a black hole in quasars. We assume that the flows are non-rotating and exposed to quasar radiation. We take…
We present a modified description of advection-dominated accretion flows (ADAF) with a geometrical viscosity. A simplified treatment of the dynamics of the flow in the inner relativistic part is suggested and results are compared with the…
Previous hydrodynamical (HD) and magnetohydrodynamical (MHD) numerical simulations of hot accretion flows have shown that the mass accretion rate decreases with decreasing radius. Two models have been proposed to explain this result. In the…
We demonstrate that generically an accretion disk around a compact object could have a new type of instability in that the accretion flow need not be symmetric with respect to the equatorial plane even when matter is supplied symmetrically…
We present a model for the high-low state transition of the X-Ray Nova GS 1124-68 (Nova Muscae 1991) observed by Ginga. The model consists of an advection-dominated accretion flow (ADAF) near the central black hole surrounded by a thin…
We perform as the first time hydrodynamic simulations to study the properties of hot accretion flow (HAF) around a neutron star (NS). The energy carried by the HAF will eventually be radiated out at the surface of the NS. The emitted…
The response of advection-dominated accretion disks to local disturbances is examined by one-dimensional numerical simulations. It is generally believed that advection-dominated disks are thermally stable. We, however, find that any…
Based on a unified description of various accretion flows, we find a long-ignored solution - the effectively optically thin accretion flow, occurring at accretion rates around Eddington value. As a consequence of radiation-pressure…
Accretion disks around compact objects are expected to enter an unstable phase at high luminosity. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion…
We investigate the structure and stability of hypercritical accretion flows around stellar-mass black holes, taking into account neutrino cooling, lepton conservation, and firstly a realistic equation of state in order to properly treat the…