We consider a sample of about 50 distant galaxy clusters at <z>0.15 (<z>=0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies and evaluatein a homogeneous way cluster velocity dispersions and optical virial masses. We apply the same procedures already successfully applied on a sample of nearby clusters in order to properly analyze the possible dynamical evolution of galaxy clusters. Moreover, we compare our results to those obtained from X-ray analyses. We do not find any evidence for an evolution of cluster properties. In particular, we find that in distant clusters the fraction of strongly substructured systems, the shape of galaxy distribution, velocity dispersion profiles and velocity anisotropies in galaxy orbits are similar to those found in nearby clusters. We do not find any evidence of a possible evolution of the relations between X--ray properties (luminosity and temperature) and velocity dispersion. We conclude that the redshift of cluster formation should be higher than that of the sample we analyze.

Dynamical Evolution of Galaxy Clusters

GIRARDI, MARISA;MEZZETTI, MARINO
2000

Abstract

We consider a sample of about 50 distant galaxy clusters at 0.15 (=0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies and evaluatein a homogeneous way cluster velocity dispersions and optical virial masses. We apply the same procedures already successfully applied on a sample of nearby clusters in order to properly analyze the possible dynamical evolution of galaxy clusters. Moreover, we compare our results to those obtained from X-ray analyses. We do not find any evidence for an evolution of cluster properties. In particular, we find that in distant clusters the fraction of strongly substructured systems, the shape of galaxy distribution, velocity dispersion profiles and velocity anisotropies in galaxy orbits are similar to those found in nearby clusters. We do not find any evidence of a possible evolution of the relations between X--ray properties (luminosity and temperature) and velocity dispersion. We conclude that the redshift of cluster formation should be higher than that of the sample we analyze.
2843942276
http://adsabs.harvard.edu/abs/2000lssx.proc..365G
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2634720
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact