Related papers: Radiatively Inefficient Accretion: Breezes, Winds …
[abridged] Radiation pressure on dust grains may be an important mechanism in driving winds in a wide variety of astrophysical systems. However, the efficiency of the coupling between the radiation field and the dusty gas is poorly…
Context. There are recent observational evidences that RY Tau may present two different outflow stages, a quiescent one and a more active one. We try to model that phenomenon. Aims. We have performed new 2.5D magneto-hydrodynamical…
Accretion flows onto underluminous black holes, such as Sagittarius A* at the center of our galaxy, are dilute (mildly collisional to highly collisionless), optically thin, and radiatively inefficient. Therefore, the accretion properties of…
To what extent can the one-dimensional slim disk model reproduce the multi-dimensional results of global radiation-hydrodynamic simulations of super-Eddington accretion? With this question in mind, we perform systematic simulation study of…
A compact object moving relative to surrounding gas accretes material and perturbs the density of gas in its vicinity. In the classical picture of Bondi-Hoyle-Lyttleton accretion, the perturbation takes the form of an overdense wake behind…
In this chapter, we summarize recent progress on the properties of accretion disks when the accretion rate exceeds the so-called Eddington limit based on multi-dimensional radiation magnetohydrodynamic simulations. We first summarize the…
We present numerical simulations of properties of a parsec-scale torus exposed to illumination by the central black hole in an active galaxy (AGN). Our physical model allows to investigate the balance between the formation of winds and…
We present evidence for the presence of a transition in the accretion properties of radio-loud sources. For a sample of radio galaxies and radio-loud quasars, selected based on their extended radio properties, the accretion rate is…
We present here numerical hydrodynamic simulations of line-driven accretion disk winds in cataclysmic variable systems. We calculate wind mass-loss rate, terminal velocities, and line profiles for CIV (1550 A) for various viewing angles.…
We consider an extreme case of disc accretion onto a gravitating centre when the viscosity in the disc is negligible. The angular momentum and the rotational energy of the accreted matter is carried out by a magnetized wind outflowing from…
We present analytical solutions for the thermodynamic (temperature, pressure, density, etc.) properties of thin accretion flows in the region within the innermost stable circular orbit (ISCO) of a Kerr black hole, the first analytical…
Radiatively inefficient accretion flows onto black holes are unstable due to both an outwardly decreasing entropy (`convection') and an outwardly decreasing rotation rate (the `magnetorotational instability'; MRI). Using a linear…
We generalise the celebrated semiclassical wavepacket approach from the adiabatic to the non-adiabatic regime. A unified description covering both of these regimes is particularly desired for systems with spatially varying band structures…
We present three-dimensional numerical magnetohydrodynamic simulations of radiatively inefficient spherical accretion onto a black hole. The simulations are initialized with a Bondi flow, and with a weak, dynamically unimportant,…
The main objective of the given work consists in the account of the basic mechanisms, which decline processes in atmosphere from adiabaticity approach, and in the study of effect non-adiabaticity on the swing of eigenmodes of atmosphere at…
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…
Non-radiating, advection-dominated, accretion flows are convectively unstable. We calculate the two-dimensional (r-theta) structure of such flows assuming that (1) convection transports angular momentum inwards, opposite to normal viscosity…
Hot Jupiters are Jupiter-sized exoplanets with close-in orbits, characterized by extreme day-night temperature contrasts due to synchronous rotation. These planets offer unique observational opportunities through transit photometry,…
In standard accretion discs, outward angular momentum transfer by viscous forces is compensated by the inward motion of the accreting matter. However, the vertical structure of real accretion discs leads to meridional circulation with…
Numerical simulations of hot accretion flow have shown that the mass accretion rate decreases with decreasing radius; consequently the density profile of accretion flow becomes flatter compared to the case of a constant accretion rate. This…