Near - infrared spectroscopy of nearby Seyfert galaxies . I . First results ⋆

We present near-infrared 1.5 – 2.5 µm moderate resolution long-slit spectra of two both parallel to ionization cone or jet and perpendicular to it. The spectra are used to study the spatial extent of the line emission, integrated masses of excited H 2 and the excitation mechanisms of interstellar gas. In all three Seyfert 2 galaxies, [Fe ii] is found to be stronger than Brγ or H 2 1–0 S(1), while in the Seyfert 1 NGC 1566 and the Seyfert 1.5 NGC 3227 Brγ is the strongest line. Broad Brγ originating from the BLR is detected in three galaxies (NGC 1386, NGC 1566 and NGC 3227), of which NGC 1386 is optically classified as Seyfert 2. In these galaxies [Fe ii] is narrow and may be X-ray excited. In all galaxies except in NGC 5128, the spatial FWHM size of H 2 1–0 S(1) nuclear core is larger perpendicular to the cone or jet than parallel to it, in agreement with AGN unified models. The values of nuclear N H2 are higher in Seyfert 2s than in Seyfert 1s, with the Seyfert 1.5 NGC 3227 lying between them. The exception to this is the Seyfert 2 NGC 1386, where two extended regions are detected parallel to cone. Coronal lines are detected in two galaxies, NGC 1386 and NGC 3227.