CONFIGURATIONS AND MORPHOLOGY OF TRIPLE GALAXIES - EVIDENCE FOR DARK-MATTER

Methods for statistical studies of geometrical configurations of tripl ets of galaxies are discussed and applied to observations. Those of th e observed triplets, which are believed to be bound isolated systems, are scattered uniformly over the area of all possible configurations a nd do not reveal any excess of hierarchical structures. Morphology of the galaxies in the triplets do not show any predominance of elliptica l galaxies which could be merger remnants. The distribution of the geo metrical structures cannot be explained by three-body dynamics, while the morphology suggests that the observed galaxies are not likely to b e results of galaxy mergers. The presence of smoothly distributed dark matter in these systems may explain the observations.