Related papers: Self-Similar Solutions for Viscous and Resistive A…
In a novel approach to studying viscous accretion flows, viscosity has been introduced as a perturbative effect, involving a first-order correction in the $\alpha$-viscosity parameter. This method reduces the problem of solving a…
Convection-dominated accretion flow (CDAF) is a promising model to explain underluminous accreting black holes in X-ray binaries and galactic nuclei. I discuss effects of angular momentum transport in viscous hydrodynamical and MHD CDAFs.…
Since the collisional mean free path of charged particles in hot accretion flows can be significantly larger than the typical length-scale of the accretion flows, the gas pressure is anisotropic to magnetic field lines. For such a large…
We obtain self-similar solutions that describe the dynamics of a self-gravitating, rotating, viscous system. We use simplifying assumptions; but explicitly include viscosity and the cooling due to the dissipation of energy. By assuming that…
The effect of a possible hydrodynamical wind on the nature of hot accretion disk solutions is studied. It is found that the advection dominated branch, in the presence of a wind, maintains the self-similar solution for the disk structure…
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…
We present global solutions of optically thin, two-temperature black hole accretion disks incorporating magnetic fields. We assume that the {\pi}{\phi}-component of the Maxwell stress is proportional to the total pressure, and prescribe the…
Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was emitted to the sides of the disk. One of the most important new invention of this theory was the…
We solve the two-dimensional hydrodynamic equations of hot accretion flow in the presence of the thermal conduction. The flow is assumed to be in steady-state and axisymmetric, and self-similar approximation is adopted in the radial…
We show that, unlike the results presented previously in the literature, the transition from an outer Shakura-Sunyaev disk (SSD) to an advection-dominated accretion flow (ADAF) is possible for large values of the viscosity parameter $\alpha…
Aiming at a general description of four basic solutions describing the accretion processes, i.e., the Shakura-Sunyaev thin disc (SSD), the Shapiro-Lightman-Eardley solution (SLE), the slim disc, and the advection-dominated accretion flow…
We obtain two-dimensional exact analytic solutions for the structure of the hot accretion flows without wind. We assume that the only non-zero component of the stress tensor is $T_{r\varphi}$. Furthermore we assume that the value of…
We present solutions to the accretion disk structure equations in which advective cooling is accounted for in a self-consistent way. It is shown that for high rates of accretion, above a critical value, when without advection there are no…
We present an analytic model in which an inefficiently radiating accretion disk drives upward wind from its surfaces. The accretion process is controlled simultaneously by a global magnetic field penetrating the disk and by a viscosity of…
A large-scale closed magnetic field can transfer angular momentum and energy between a black hole (BH) and its surrounding accretion flow. We investigate the effects of this magnetic coupling (MC) process on the dynamics of a hot accretion…
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…
We present the effects of ordered large scale magnetic field on the structure of supercritical accretion flow in the presence of outflow. In the cylindrical coordinates ($r, \varphi,z$), We write the 1.5 dimensional, the steady state…
The source of viscosity in astrophysical accretion flows is still a hotly debated issue. We investigate the contribution of convective turbulence to the total viscosity in a self-consistent approach, where the strength of convection is…
The observation of the hot gas surrounding Sgr $A^*$ and a few other nearby galactic nuclei imply that electron and proton mean free paths are comparable to the gas capture radius. So, the hot accretion flows is likely to proceed under…
This paper explores the effects of large-scale magnetic fields in hot accretion flows for asymmetric configurations with respect to the equatorial plane. The solutions that we have found show that the large-scale asymmetric magnetic field…