Long-slit spectroscopy of three low-luminosity Seyfert-1 galaxies

Medium-resolution long-slit spectroscopy of NGC 1365, NGC 6814 and NGC 7314 is presented. We obtain V_rot_=160km/s (for an uncertain i = 11deg) and 170km/s for the galactic disks of NGC 6814 and NGC 7314, respectively. These values are normal for their blue luminosities according to a relation given in Rubin (1983). The apparent central gradients of the rotation curves are moderate and yield Keplerian estimates for the nuclear mass (inside R=100pc) of 10^7-8^M_sun_ and 6x10^6^M_sun_, respectively. These values only slightly exceed the black hole masses estimated from broad-line properties. The nuclear narrow-line ratios lie within the general range of Seyferts. However, NGC 6814 exhibits a large [NII]/Hα ratio, which can be explained by the presence of a high density component. Circumnuclear narrow-line velocities in NGC 1365 are in agreement with earlier data. While most extranuclear line intensity ratios of [NII], [SII] (and [OI] as far as available) to Hα are typical for HII-region type objects there is a region extending from 13" to 30" west of the nucleus, which exhibits [NII]λ6583/Hα=2.6+/-0.3 and [SII]λλ6716,6731/Hα<0.4. This unusual combination can be explained by a factor of ~5 nitrogen enhancement. About 6" southeast of the nucleus we detected blueshifted [OIII] and an increase in [OIII]/Hβ apparently related to the radiation and outflow cone invoked by others. We emphasize the lack of a detailed line ratio map in the cone area. To our knowledge there is so far no unambiguous evidence for a classical Seyfert narrow-line region in NGC 1365, although it reveals strong broad Hα.