I subscribed to the theory that black holes in the centers of galaxies, the supermassive ones were all surrounded by a torus and it was how the galactic plane was angled toward us that made them appear different. NASA’s Wide-field Infrared Survey Explorer (WISE) casts a shadow doubt on this so-called unified theory of active supermassive black holes:
From the Wise site:
Active, supermassive black holes at the hearts of galaxies tend to fall into two categories: those that are hidden by dust, and those that are exposed. Data from NASA’s Wide-field Infrared Survey Explorer, or WISE, have shown that galaxies with hidden supermassive black holes tend to clump together in space more than the galaxies with exposed, or unobscured, black holes.