AGN anisotropic radiative feedback set by black hole spin
  We consider the impact of anisotropic radiation on the active galactic
nucleus (AGN) radiative dusty feedback. The radiation pattern originating from
the accretion disc is determined by the central black hole (BH) spin. Here we
analyse how such BH spin-induced angular dependence affects the dynamics and
energetics of the radiation pressure-driven outflows, as well as AGN
obscuration and BH accretion. In addition, we explore the effect of a spatially
varying dust-to-gas ratio on the outflow propagation. We obtain two distinct
trends for high-spin and low-spin objects, providing a direct connection
between anisotropic feedback and BH spin. In the case of maximum spin, powerful
quasi-spherical outflows can propagate on large scales, at all inclination
angles with fairly uniform energetics. In contrast, in the case of zero spin,
only weaker bipolar outflows can be driven in the polar directions. As a
result, high BH spins can efficiently clear out the obscuring gas from most
directions, whereas low BH spins can only remove dusty gas from the polar
regions, hence also determining the overall AGN obscuration geometry. Due to
such anisotropic feedback, high BH spins can prevent accretion of gas from most
directions (except in the equatorial plane), while low BH spins allow inflows
to proceed from a wider range of directions. This may have important
implications for the BH growth in the early Universe. Anisotropic radiative
dusty feedback, ruled by the BH spin, may thus play a major role in shaping AGN
evolution over cosmic time.
