Question

 Describe the nature of the central engine in an AGN. 

Answer 1

The central engine of a typical AGN is believed to contain a supermassive black hole of mass ∼10⁸M _⊙ and Schwarzschild radius ∼3$\cdot$10¹¹ m (2 AU). Infalling material is thought to form an accretion disc around the black hole, converting gravitational energy into thermal energy and radiation.