We perform two-dimensional hydrodynamical simulations of slowly rotating accretion flows in the region of 0.01 − 7 pc around a supermassive black holes with M BH = 10 8 M . The accretion flow is irradiated by the photons from the central active galactic nucleus (AGN). In addition to the direct radiation from the AGN, we have also included the "re-radiation", i.e., the locally produced radiation by Thomson scattering, line and bremsstrahlung radiation. Compare to our previous work, we have improved the calculation of radiation force due to the Thomson scattering of X-ray photons from the central AGN. We find that this improvement can significantly increase the mass flux and velocity of outflow. We have compared the properties of outflow -including mass outflow rate, velocity, and kinetic luminosity of outflow -in our simulation with the observed properties of outflow in AGNs and found that they are in good consistency. This implies that the combination of line and re-radiation forces is the possible origin of observed outflow in luminous AGNs.

We solve the radiation-hydrodynamic (RHD) equations of supercritical accretion flows in the presence of radiation force and outflow by using self similar solutions. Compare with the pioneer works, in this paper we consider power-law function for mass inflow rate asṀ ∝ r s . We found that s = 1 when the radiative cooling term is included in the energy equation. Correspondingly, the effective temperature profile with respect to the radius was obtained as T eff ∝ r −1/2 . In addition, we investigated the influence of the outflow on the dynamics of the accretion flow. We also calculated the continuum spectrum emitted from the disk surface as well as the bolometric luminosity of the accretion flow. Furthermore, our results show that the advection parameter, f , strongly depends on mass inflow rate.

We present the two-dimensional inflow-outflow solutions of radiation hydrodynamic (RHD) equations of supercritical accretion flows. Compared with prior studies, we include all components of the viscous stress tensor. We assume steady state flow and use self-similar solutions in the radial direction to solve the equations in r − θ domain of the spherical coordinates. The set of differential equations have been integrated from the rotation axis to the equatorial plane. We find that the self-similarity assumption requires that the radial profile of density is described by ρ(r) ∝ r −0.5 . Correspondingly, the radial profile of the mass inflow rate decreases with decreasing radii as Ṁin ∝ r. Inflow-outflow structure has been found in our solution. In the region θ > 65 • there exist inflow while above that flow moves outward and outflow could launch. The driving forces of the outflow are analyzed and found that the radiation force is dominant and push the gas particles outwards with poloidal velocity ∼ 0.25c. The properties of outflow are also studied. The results show that the mass flux weighted angular momentum of the inflow is lower than that of outflow, thus the angular momentum of the flow can be transported by the outflow. We also analyze the convective stability of the supercritical disk and find that in the absence of the magnetic field, the flow is convectively unstable. Our analytical results are fully consistent with the previous numerical simulations of the supercritical accretion flow.

We solved the set of two-dimensional magnetohydrodynamic (MHD) equations for optically thin black hole accretion flows incorporating the toroidal component of the magnetic field. Following global and local MHD simulations of black hole accretion disks, the magnetic field inside the disk is decomposed into a large-scale field and a fluctuating field. The effects of the fluctuating magnetic field in transferring the angular momentum and dissipating the energy are described through the usual α description. We solved the MHD equations by assuming a steady-state and radially self-similar approximation in the r − θ plane of the spherical coordinate system. We found that as the amount of magnetic field at the equatorial plane increases, the heating by the viscosity decreases. In addition, the maximum amount of the heating by the viscous dissipation is produced at the midplane of the disk, while that of the heating by the magnetic field dissipation is produced at the surface of the disk. Our main conclusion is that in terms of the no-outflow solution, thermal equilibrium still exists for the strong magnetic field at the equatorial plane of the disk.

We solve the 2D 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 a self-similar approximation is adopted in the radial direction. In this hydrodynamic study, we consider the viscous stress tensor to mimic the effects of the magnetorotational instability for driving angular momentum. We impose the physical boundary conditions at both the rotation axis and the equatorial plane and obtain the solutions in the full r −θ space. We have found that thermal conduction is an indispensable term for investigating the inflow-wind structure of the hot accretion flows with very low mass accretion rates. One of the most interesting results here is that the disk is convectively stable in hot accretion mode and in the presence of the thermal conduction. Furthermore, the properties of wind and also its driving mechanisms are studied. Our analytical results are consistent with previous numerical simulations of hot accretion flow.