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J. R. Cortes (Universidad de Chile/ Yale University), J. D. P. Kenney (Yale University)
NGC 4424 is a peculiar, gas-deficient, Virgo Cluster Sa galaxy which is probably the result of a merger. This galaxy seems to deviate from the Tully-Fisher relationship, as shown by Kenney et al (1996) and Rubin et al (1999). We present stellar and gas kinematics of NGC 4424 measured with Integral Field Spectroscopy using the Densepak fiber array on the WIYN telescope. Using a cross-correlation technique, we derive velocities and velocity dispersions of the stars thoughout the central region of the galaxy. We find that the mean line-of-sight velocities for both gas and stars are approximately a factor of 2 smaller than would be expected for the rotational motions of a galaxy of its luminosity and apparent inclination. Preliminary estimates of the stellar velocity dispersion are also lower than would be expected for the Faber-Jackson relationship. We discuss possible explanations for this behaviour, including the possibility that this disturbed galaxy is rotating in a plane different than the plane of the apparent disk, and is a tumbling object.
The author(s) of this abstract have provided an email address for comments about the abstract: cortes@astro.yale.edu