Shape of the Galactic Orbits in the CNOC1 Clusters

We present an analysis of the orbital properties in 9 intermediate-redshiftscluster of the CNOC1 survey and we compare them to a control sample of 12nearby clusters. Similar to the nearby elliptical galaxies, the bulge-dominatedgalaxies in clusters at redshifts ~0.1-0.4 present orbits that are moreeccentric than those for disk-dominated galaxies. However, the orbitalsegregation is less significant than that found for elliptical and spiralgalaxies in nearby cluster. When galaxies are separated by colors - redgalaxies with colors in the rest frame (U-V)_o > 1.4, and blue galaxies with(U-V)_o =< 1.4 - the strongest orbital segregation is found. Therefore, thesegregation we found seems to modify more efficiently the star formationactivity than the internal shape of the galaxies. When we compare the orbits ofearly-type galaxies at intermediate-redshift with those for z=0, they seem todevelop significant changes getting much more eccentric. A different behavioris observed in the late-type galaxies, which present no-significant evolutionin their orbit shapes.Comment: Accepted for publication in ApJ, April 2000. Latex with aaspp4.sty, 20 pages, 4 tables, 6 eps figure