THE MORPHOLOGY OF CLUSTERS OF GALAXIES

Available deep samples of positional and photometric data on clusters of galaxies are analysed to give estimates of ellipticity and position angle at various limiting magnitudes and effective radii. Comparison of the ellipticity data with those for elliptical galaxies shows that clusters are apparently more elongated than elliptical galaxies. Comparison of position angles with those of cD galaxies in the clusters shows significant evidence for alignment. Both of these data are consistent with an adiabatic perturbation theory of cluster and galaxy formation. © 1980 Royal Astronomical Society. Provided by the NASA Astrophysics Data System.