Unformatted text preview: Galaxy content: the fraction of E/S0 galaxies depends on local galaxy density (Dressler 1980 ApJ 236, 351) and thus changes markedly from the outskirts to a cluster core (see the environmental-impact lecture . Only loose or subcluster environments have many spirals. As we've already seen, this changes with cosmic epoch in the Butcher-Oemler effect. Symmetry: the most concentrated clusters are most symmetric and regular, approaching in some cases an equipartition distribution. One may seek substructure in position or velocity space. Mass segregation: If the cluster evolves far enough dynamically, energy will be equally distributed among members, so that the more massive ones move more slowly and sink to the center. There is some evidence for this effect in a few clusters....
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- Fall '10
- Astronomy, mass segregation, Annual Reviews article, Central concentration High, local galaxy density