The AGN Torus --- a Paradigm Change
The variety of observations of Active Galactic Nuclei (AGN) have been
classified with a simple unified scheme: The nuclear activity is powered
by a central massive black hole that drives radio emitting jets and
ionizes surrounding line-emitting clouds. The whole system is surrounded
by a dusty torus, and the observer's orientation with respect to this
obscuring torus determines the appearance of the AGN. Pole-on viewing
gives rise to superluminal jets and Seyfert 1 line spectrum, edge-on
results in extended radio lobes and Seyfert 2 lines. The torus is
comprised of optically thick dusty clouds in a rotating configuration
with roughly equal vertical and radial dimensions.
