Dynamics of Line‐driven Disk Winds in Active Galactic Nuclei. II. Effects of Disk Radiation

Abstract

We explore consequences of a radiation driven disk wind model for mass\noutflows from active galactic nuclei (AGN). We performed axisymmetric\ntime-dependent hydrodynamic calculations using the same computational technique\nas Proga, Stone and Kallman (2000). We test the robustness of radiation\nlaunching and acceleration of the wind for relatively unfavorable conditions.\nIn particular, we take into account the central engine radiation as a source of\nionizing photons but neglect its contribution to the radiation force.\nAdditionally, we account for the attenuation of the X-ray radiation by\ncomputing the X-ray optical depth in the radial direction assuming that only\nelectron scattering contributes to the opacity. Our new simulations confirm the\nmain result from our previous work: the disk atmosphere can 'shield' itself\nfrom external X-rays so that the local disk radiation can launch gas off the\ndisk photosphere. We also find that the local disk force suffices to accelerate\nthe disk wind to high velocities in the radial direction. This is true provided\nthe wind does not change significantly the geometry of the disk radiation by\ncontinuum scattering and absorption processes; we discuss plausibility of this\nrequirement. Synthetic profiles of a typical resonance ultraviolet line\npredicted by our models are consistent with observations of broad absorption\nline (BAL) QSOs.\n