Spectroscopy and photometry of elliptical galaxies. II - The spectroscopic parameters

Abstract

Radial velocities, velocity dispersions, and Mg line-strength indices are measured for 469 elliptical galaxies using four telescope/detector configurations. The data have been put on a common scale; the scatter of repeat measurements indicates an uncertainty of + or - 10 percent and + or - 0.01 mag for single determinations of sigma and Mg2, respectively. A correction for the change in linear aperture size as a function of distance has been derived, and mean corrected values of sigma and Mg2 are adopted. The galaxies have been assigned to groups by combining the present velocities with those in the redshift catalog of Huchra et al. (1983) and using the algorithm of Huchra and Geller (1982).