ACTIVE GALACTIC NUCLEUS OBSCURATION FROM WINDS: FROM DUSTY INFRARED-DRIVEN TO WARM AND X-RAY PHOTOIONIZED

We present calculations of active galactic nucleus winds at ∼parsec scales along with the associated obscuration. We take into account the pressure of infrared radiation on dust grains and the interaction of X-rays from a central black hole with hot and cold plasma. Infrared radiation (IR) is incorporated in radiation-hydrodynamic simulations adopting the flux-limited diffusion approximation. We find that in the range of X-ray luminosities L = 0.05-0.6 LEdd, the Compton-thick part of the flow (aka torus) has an opening angle of approximately 72°-75° regardless of the luminosity. At L ∼> 0.1, the outflowing dusty wind provides the obscuration with IR pressure playing a major role. The global flow consists of two phases: the cold flow at inclinations θ ∼> 70° and a hot, ionized wind of lower density at lower inclinations. The dynamical pressure of the hot wind is important in shaping the denser IR-supported flow. At luminosities ≤0.1 LEdd episodes of outflow are followed by extended periods when the wind switches to slow accretion.