Type 2 Counterparts of Narrow - Line Seyfert 1 Galaxies

Unified models of Seyfert galaxies, based on viewing angles, successfully explain the observed differences between type 1 and 2 Seyferts. The existence of a range in accretion rates (ṁ ∼ 0.001− 1) relative to the Eddington rate (from broad-line Seyfert 1s to narrow-line Seyfert 1s or NLS1s) and the unification of Seyfert galaxies imply that there must be type 2 counterparts of NLS1 galaxies i.e., Seyfert 2s with high accretion rate or small black hole mass. One such Seyfert 2, NGC 5506, has already been unmasked based on near infra-red spectroscopy. Here we confirm the above result, and present evidence for two additional type 2 counterparts of NLS1s based on XMM-Newton observations. The three AGNs NGC 7314, NGC 7582 and NGC 5506, with a type 1.9/2 optical spectrum, show extremely rapid variability by factors > 2.4, ∼ 1.3, and ∼ 1.7 in 200 s, 350 s and 300 s, respectively, and steep 2 − 12 keV spectrum (Γ & 2) in their intrinsic X-ray emission, characteristic of NLS1 galaxies. These observations establish the ‘obscured NLS1 galaxies’ as a subclass of Seyfert 2 galaxies. Subject headings: accretion, accretion disks – galaxies: active – X-rays: galaxies