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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 into account X-ray heating and the radiation force due to electron scattering and spectral lines. To compute the radiation field, we consider a standard accretion disk as a source of UV photons and a spherical central object as a source of X-rays. The gas temperature and ionization state in the flow are calculated self-consistently from the photoionization and heating rate of the central object. We find that for a 10e8 MSUN black hole with an accretion luminosity of 0.6 of the Eddington luminosity the flow settles into a steady state and has two components: (1) an equatorial inflow and (2) a bipolar inflow/outflow with the outflow leaving the system along the disk rotational axis. The inflow is a realization of a Bondi-like accretion flow. The second component is an example of a non-radial accretion flow which becomes an outflow once it is pushed close to the rotational axis where thermal expansion and the radiation pressure accelerate it outward. Our main result is that the existence of the above two flow components is robust to the outer boundary conditions and the geometry and spectral energy distribution of the radiation field. However, the flow properties are not robust. In particular, the outflow power and collimation is higher for the radiation dominated by the UV/disk emission than for the radiation dominated by the X-ray/central engine emission. Our most intriguing result is that a very narrow outflow driven by radiation pressure on lines can carry more energy and mass than a broad outflow driven by thermal expansion.
We study the axisymmetric, time-dependent hydrodynamics of rotating flows that are under the influence of supermassive black hole gravity and radiation from an accretion disk surrounding the black hole. This work is an extension of the earlier work p
We discuss the role that magnetic fields in low luminosity accretion flows can play in creating and maintaining a multi-phase medium, and show that small magnetically-confined clouds or filaments of dense cold gas can dramatically reprocess the `prim
The non-monotonicity of the local speed of sound in dense matter at baryon number densities much higher than the nuclear saturation density ($n_0 approx 0.16,$fm$^{-3}$) suggests the possible existence of a non-convex thermodynamics which will lead t
We discuss technologies for micro-arcsec echo mapping of black hole accretion flows in Active Galactic Nuclei (AGN). Echo mapping employs time delays, Doppler shifts, and photoionisation physics to map the geometry, kinematics, and physical condition
Fascination with glassy states has persisted since Fisher introduced the vortex-glass as a new thermodynamic phase that is a true superconductor that lacks conventional long-range order. Though Fishers original model considered point disorder, it was