Digital objective prism spectroscopy and astrometry: Quantitative methods and application to high-velocity stars

We describe methods for extracting quantitative spectra and astrometric pos itions from objective prism plates. In particular, we have studied 7161 sta rs in eight fields along the south Galactic meridian using the 6 degrees 4 degrees objective prisms on the Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory. In this paper we concentrate on techniques for deriving radial velocities and astrometric positions front opposed dispersi on plate pairs. For our data the typical accuracy in radial velocity is sim ilar to 8 km s(-1). A catalog of 108 stars with high radial velocities is p resented, which is complete (and unbiased in either kinematics or metallici ty) to a limiting B magnitude of 12.5 in the eight fields studied. Only two of this sample of 108 stars have previously reported radial velocities.