Quantifying substructure in galaxy clusters
Received 25 January 1999 / Accepted 21 December 1999
Substructure in galaxy clusters can be quantified with the robust statistics (Dressler and Shectman 1988) which uses velocity kinematics and sky projected positions. We test its sensitivity using dissipationless numerical simulations of cluster formation. As in recent observations, about 30% of the simulated clusters show substructure, but the exact percentage depends on the chosen limit for defining substructure, and a better discriminator is the distribution function of the statistics. The Dressler-Shectman statistics correlate well with other subcluster indicators, but with large scatter due to its sensitivity to small infalling groups and projection effects.
Key words: galaxies: clusters: general cosmology: observations cosmology: theory
Send offprint requests to: A. Knebe
This article contains no SIMBAD objects.
© European Southern Observatory (ESO) 2000
Online publication: February 25, 2000