Position-velocity diagrams of ionized gas in the inner regions of disk   galaxies
  We use long-slit spectroscopy along the major axis of a sample of 23 nearby disk galaxies to study the kinematic properties of the ionized-gas component in their inner regions. For each galaxy, we derive the position-velocity diagram of the ionized gas from its emission lines. We discuss the variety of shapes observed in such position-velocity diagrams by comparing the gas velocity gradient, velocity dispersion and integrated flux measured in the inner (r +/-1'') and outer regions (r +/-4''). This kind of analysis allows the identification of galaxies which are good candidates to host a circumnuclear Keplerian gaseous disk rotating around a central mass concentration, and to follow up with Hubble Space Telescope observations. 
J.G. Funes (Vatican Obs.), E.M. Corsini (Univ. of Padova), M.   Cappellari (Leiden Obs.), A. Pizzella (Univ. of Padova), J.C...