THE ASTRONOMICAL JOURNAL    VOLUME 113, IN PRESS                   JANUARY 1997

                       KINEMATIC PROFILES OF S0 GALAXIES

                                 DAVID FISHER

   Kapteyn Astronomical Institute, University of Groningen, Postbus 800,
         9700 AV Groningen, The Netherlands and UCO/Lick Observatory,
   Board of Studies in Astronomy and Astrophysics, University of California,
                             Santa Cruz, CA 95064
                      Electronic mail: fish@astro.rug.nl


                                   ABSTRACT

    Stellar rotation curves, velocity dispersion profiles, and line of
    sight velocity distributions (LOSVD) as derived from absorption-lines
    are presented for the major axes of 18 S0 and two elliptical
    galaxies. Ionized gas rotation curves and dispersions were measured
    from the [OIII] 5007 A emission line in the 9 S0 galaxies displaying
    this feature. Minor-axis results are given for 14 of the S0 galaxies
    and one of the ellipticals.

    A wide range of behaviors are observed in the rotation and velocity
    dispersion profiles. These variations could be the result of the
    superposition of stars and gas belonging to the disks and bulges as
    well as the possible influences of bars, nuclear disks, and
    warps. Deviations from a Gaussian LOSVD are found along the major axes
    of all the galaxies in our sample. As parametrised by the Gauss-Hermite
    series of orthogonal functions, asymmetric deviations are always found
    in the inner regions of the S0 galaxies such that the prograde wing of
    the LOSVD is steeper than the retrograde wing. This is similar to the
    behavior observed in elliptical galaxies. However, at larger radii
    these asymmetries can change their sign. We find that in 9 of the 18 S0
    galaxies a high-speed tail to the LOSVD develops along the major-axis
    beyond the central regions. In 3 of these 9 objects the LOSVD
    asymmetries display a second change of sign with radius such that a
    low-speed tail is again present and persists to our last measured
    values.

    No correlations were found between the sizes of the stellar velocity
    dispersion gradients and either central velocity dispersion, absolute
    magnitude, disk-to-bulge ratio, Mg2 or Fe line strength gradients. For
    the objects in our sample with edge-on orientations a comparison
    between the minor-axis 'bulge' velocity dispersion gradients and those
    found in elliptical galaxies indicates that the S0 bulges display, on
    average, logarithmic gradients approximately 4 times steeper than those
    found in normal luminous ellipticals.

    A number of galaxies show particularly interesting features. For the
    LINER S0 galaxy NGC 3998 we find that the velocity dispersion profiles
    of both the stars and gas rise sharply towards the center reaching
    nuclear values of sigma ~ 320 km/s. Nuclear disks of rapidly rotating
    gas are found in NGC 4350 and NGC 4762. A nuclear stellar disk is
    apparent in the edge-on galaxy NGC 4111 and an extended disk of
    counterrotating gas is observed in the barred S0 NGC 3941.