We propose a new dynamical model for obscuring tori of active galactic nuclei motivated by our recent radiative magnetohydrodynamics simulation. The model consists of a momentum-driven outflow from the inner edge powered by ultraviolet and infrared radiation, as well as a mid-plane inflow feeding it. The outflow in our model occupies a large solid angle and has high enough latitude to provide substantial covering in the optical and the ultraviolet. We consider how central irradiation may affect the inflow, and what heavy mass loss to the outflow may imply for the inflow.
Questions for discussion:
- Any reasonable torus wind model (e.g. thermally driven, radiation-driven, magnetocentrifugal wind) predicts ~0.1 M⊙/year for 1e7 solar mass AGN. Unless the torus is very Compton thick and hence contains a lot of mass, it can only last ~10s of orbits. How can mass be supplied quickly enough for the torus to be in a steady state? Or is the torus always a transient phenomenon?
- How can observations constrain the geometrical thickness and rotational profile of the inflow portion of the torus?
- Besides with interferometry, how can the radiation-driven outflow be observed and its properties compared with simulations (e.g. with line ratios)?
- Is there any connection between the inner surface of the torus and the BLR? Is line-driving significant near the inner edge?