Galaxy Associations within the Coma Cluster

Abstract

The mean redshift of the core of the Coma cluster - cz = 6953 km s^{-1} and its dispersion σ=949 km s^{-1} are obtained by means of the analysis of the substructures of this cluster by using the S-tree method. The existence of three subgroups of galaxies is revealed, one of them is associated with the cD galaxy NGC 4874, the other -- with NGC 4889. It is argued that these subgroups are {\it galaxy associations}, i.e. galactic dynamical entities moving within the main cluster. Thus we conclude that the non-stationarity of the dynamical processes ongoing in the Coma core is due to the merging of small-scale galaxy associations, rather than of two equal sized clusters. We provide the lists of the galaxies of the associations, the observational study of which can be of particular interest.

to appear in New Astronomy

Cited by in corpus (9)

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• Keck/LRIS Spectroscopic Confirmation of Coma Cluster Dwarf Galaxy Membership Assignments
• Globular cluster systems in elliptical galaxies of Coma
• Intergalactic globular clusters and the faint end of the galaxy number counts in A1656 (Coma)
• Constraining the baryon loading factor of AGN jets: implication from the gamma-ray emission of the Coma cluster