A MULTIDIMENSIONAL APPROACH TO ESTIMATING PECULIAR VELOCITIES OF GALAXIES

We examine a possibility for improving the estimates of peculiar veloc ities of galaxies using several distance indicators and several calibr ators. Using 39 ellipticals and 120 edge-on spirals, we show that a mu ltidimensional approach is 1.1-1.3 times more accurate than the Faber- Jackson or Tully-Fisher methods. In the case of ellipticals, it turns out that the most effective distance indicator is the stellar magnitud e: calibrators for this include the velocity dispersion, the surface b rightness, and the color index. In the case of edge-on spirals, it tur ns out that the best indicator is the diameter of the galaxy in red li ght: calibrators for this include the H I line width and the ratio of the apparent axes of the galaxy image (there are no color indices). Fo r certain galaxies in our sample, the peculiar velocities estimated fr om the multidimensional approach are substantially different from thos e obtained by the Faber-Jackson or Tully-Fisher methods.