Seyfert 1 mutation of the classical Seyfert 2 nucleus NGC 7582

Abstract

We report the transition towards 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 Ha line width is of about 12000 km/s. 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.