Leave a Comment Using the hectospec instrument at the MMTO, astronomers are studying the mass distribution in galaxy clusters. The basic techniques were developed by M. J. Geller (Smithsonian Astrophysical Observatory) and her collaborators some time ago. The data are now good enough to get excellent results for a large sample of clusters.
Two large surveys recently completed are the Hectospec Cluster Survey (HeCS) and the Arizona Cluster Redshift Survey (ACReS).
