  We study the interaction of feedback from active galactic nuclei (AGN) and a
multi-phase interstellar medium (ISM), in simulations including explicit
stellar feedback, multi-phase cooling, accretion-disk winds, and Compton
heating. We examine radii ~0.1-100 pc around a black hole (BH), where the
accretion rate onto the BH is determined and where AGN-powered winds and
radiation couple to the ISM. We conclude: (1) The BH accretion rate is
determined by exchange of angular momentum between gas and stars in
gravitational instabilities. This produces accretion rates ~0.03-1 Msun/yr,
sufficient to power luminous AGN. (2) The gas disk in the galactic nucleus
undergoes an initial burst of star formation followed by several Myrs where
stellar feedback suppresses the star formation rate (SFR). (3) AGN winds
injected at small radii with momentum fluxes ~L/c couple efficiently to the ISM
and have dramatic effects on ISM properties within ~100 pc. AGN winds suppress
the nuclear SFR by factors ~10-30 and BH accretion rate by factors ~3-30. They
increase the outflow rate from the nucleus by factors ~10, consistent with
observational evidence for galaxy-scale AGN-driven outflows. (4) With AGN
feedback, the predicted column density distribution to the BH is consistent
with observations. Absent AGN feedback, the BH is isotropically obscured and
there are not enough optically-thin sightlines to explain Type-I AGN. A
'torus-like' geometry arises self-consistently as AGN feedback evacuates gas in
polar regions.
