Related papers: Compton Heated Outflow from CDAFs
All high temperature accretion solutions including ADAF are physically thick, so outgoing radiation interacts with the incoming flow, sharing as much or more resemblance with classical spherical accretion flows as with disk flows. We…
We study the thermal structure of the widely adopted two-dimensional advection dominated accretion flow (ADAF) of Narayan & Yi (1995a). The critical radius for a given mass accretion rate, outside of which the optically thin hot solutions…
We investigate accretion disc models for the X-ray emission of Seyfert-1 galaxies and the hard state of black-hole X-ray binaries. We concentrate on two hot accretion disc models: advection-dominated accretion flow (ADAF) and recently found…
Recent papers discussing advection dominated accretion flows (ADAF) as a solution for astrophysical accretion problems should be treated with some caution because of their uncertain physical basis. The suggestions underlying ADAF involve…
Observations and numerical magnetohydrodynamic (MHD) simulations indicate the existence of outflows and ordered large-scale magnetic fields in the inner region of hot accretion flows. In this paper we present the self-similar solutions for…
The geometry of the accretion flow around stellar mass and supermassive black holes depends on the accretion rate. Broad iron emission lines originating from the irradiation of cool matter can indicate that there is an inner disk below a…
Outflows and convective motions in accretion flows have been intensively discussed recently in the context of advection-dominated accretion flow (ADAF) based on two-dimensional (2D) and three-dimensional (3D) hydrodynamical simulations. We,…
We study the energetics of the accretion-induced outflow and then plausible jet around black holes/compact objects using a newly developed disc-outflow coupled model. Inter-connecting dynamics of outflow and accretion essentially upholds…
Recent numerical simulations of radiatively inefficient accretion flows onto compact objects have shown that convection is a general feature in such flows. Dissipation of rotational and gravitational energies in the accretion flows results…
As the luminosity of an accreting black hole drops to a few percent of Eddington, the spectrum switches from the familiar soft state to a hard state that is well-described by a distended and tenuous advection-dominated accretion flow…
Two significant progresses have been made in the past years on our understanding of hot accretion flows. One is that only a small fraction of accretion flow available at the outer boundary can finally falls onto the black hole while most of…
We solve for the structure of a hot accretion disc with unsaturated thermal Comptonisation of soft photons and with advection, generalizing the classical model of Shapiro et al. The upper limit on the accretion rate due to advection…
At luminosities below a few percent of Eddington, accreting black holes switch to a hard spectral state which is very different from the soft blackbody-like spectral state that is found at higher luminosities. The hard state is…
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…
We present self-similar solutions for advection -dominated accretion flows with thermal conduction in the presence of outflows. Possible effects of outflows on the accretion flow are parametrized and a saturated form of thermal conduction,…
The boundary layers of weakly-magnetized white dwarfs (WDs) accreting at rates <=10^16 g/s are radially extended, hot, optically-thin, and they advect some of their internally-dissipated energy (Narayan & Popham 1993). Motivated by this, I…
The broad-line region (BLR) disappears in many low-luminosity AGNs, the reason of which is still controversial. The BLRs in AGNs are believed to be associated with the outflows from the accretion disks. Most of the low-luminosity AGNs…
Based on no-outflow assumption, we investigate steady state, axisymmetric, optically thin accretion flows in spherical coordinates. By comparing the vertically integrated advective cooling rate with the viscous heating rate, we find that…
Optically thin accretion plasmas can reach ion temperatures $T_{\rm i} \geq 10^{10}$K and thus trigger nuclear reactions. Using a large nuclear interactions network, we studied the radial evolution of the chemical composition of the…
We find a new two-temperature hot branch of equilibrium solutions for stationary accretion disks around black holes. In units of Eddington accretion rate defined as $10L_{\rm Edd}/c^2$, the accretion rates to which these solutions…