1995A&AS..110..131R

Isolated mixed morphology pairs are composed of an early and a late type galaxy. They are an ideal laboratory for studying the response of gas to a gravitational instability. We present data from a kinematic and photometric study of six mixed pairs. High resolution rotation and velocity dispersion curves, for both gas and stellar components, are presented. Slit orientations were along the major axis of the spiral and, in most of the cases, along the line connecting the galaxy nuclei. B and V luminosity and geometrical profiles are also presented. Photometric parameters including effective radius and disk scale length are also presented. Data on the [N II](6583)/Hα emission line ratio provide a further insight into physical conditions of the gas. Half of the early-type components show lenticular morphology involving a well defined disk. Most late-type components show Grand Design spiral structure. Rotation curves of both members appear normal along the axes studied. The nuclear region of NGC 5297 is the single case where the gaseous component shows evidence for an apparent counter rotation relative to the stellar component, probably due to the presence of a bar. There is evidence in the early type member NGC 5953, and possibly also in NGC 5296, that the gas component has been acquired from the spiral member of the pair. The gas in these objects is concentrated in nuclear star forming regions as deduced from (B-V) color. This may be evidence for mass transfer induced activity (cross-fuelling) in these pairs. The nuclear gas in NGC 5297, 6962 and E 297-G-8 shows a reversal of the [N II] to Hα emission line intensity ratio. This indicator along with the [O III](5007)/Hβ ratio suggests that these nuclei show low level (LINER) activity.