Seyfert 1 Mutation of the Classical Seyfert 2 Nucleus NGC 7582

We report the transition toward a type 1 Seyfert experienced by the classical type 2 Seyfert nucleus in NGC 7582. The transition, found at most 20 days from its maximum peak, presents a unique opportunity to study these rare events in detail. At maximum, the Hα line width is about 12,000 km s^-1. We examine three scenarios that could potentially explain the transition: capture of a star by a supermassive black hole, a reddening change in the surrounding torus, and the radiative onset of a Type IIn supernova exploding in a compact nuclear/circumnuclear starburst.

Based on observations collected at the European Southern Observatory at La Silla, Chile.