Evidence for substructure in rich clusters of galaxies from radial-velocity measurements

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/114694· OSTI ID:6995672

Dressler, A; Shectman, S A

New radial-velocity measurements in 15 clusters of galaxies are used to look for substructure. With a new statistical test that looks for deviations of the local velocity mean and dispersion from the global values, it is found that most of the clusters in the sample show significant subclustering. In 30-40 percent of the cases, the subclusters contain a large fraction of the galaxies found in the main body of the cluster. This result is in good agreement with earlier work by Geller and Beers (1982) based on number counts. The large fraction of clusters with significant substructure, along with evidence based on radial-velocity dispersion profiles, suggest that many, perhaps most, rich clusters did not collapse in single, coherent events. 22 references.

• Research Organization: Mount Wilson and Las Campanas Observatories, Pasadena, CA (USA)
• OSTI ID: 6995672
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 95; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMOLOGY
GALACTIC EVOLUTION
GALAXY CLUSTERS
MATHEMATICS
MORPHOLOGY
RADIAL VELOCITY
STATISTICS
VELOCITY