1994A&A...290...40M

NGC 5506 is a peculiar Seyfert (Sy) galaxy: it has a Sy2-like optical spectrum, but broad permitted infrared lines and a high X-ray luminosity as compared with Sy2's. By means of optical long slit spectroscopical observations, we obtained the velocity field, density and reddening of the narrow line region (NLR), as well as a detailed analysis of several line ratios along the slit. Double peaked lines are observed in part of the extended NLR. They can be explained if the emitting clouds move outward through two cones coaxial with the galactic disk, and are optically thick to Hα. Line ratios are consistent with a Sy1-like nucleus (normalized to the X-ray luminosity of NGC 5506) illuminating the clouds, and hidden to our line of sight by a molecular torus. We also identify a circumnuclear star formation region (few hundred pc in size) with a star formation rate (SFR) of about 2x10^–3M_☉/yr/pc².