The spatial distribution, kinematics, and dynamics of the galaxies in the region of Abell 2634 and 2666

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Abstract
A total of 663 galaxies with known redshifts in a 12 degrees x 12 degrees field centered on A2634, including 211 new measurements, are used to study in detail the structure of the region. In it we find six main galaxy concentrations: the nearby clusters A2634 and A2666, two groups in the vicinity of A2634, and two distant clusters at similar to 18,000 (A2622) and similar to 37,000 km s(-1) seen in projection near the core of A2634. For A2634, the most richly sampled of those concentrations, we are able to apply strict cluster membership criteria. Two samples-one containing 200 galaxies within 2 degrees from the cluster center and a second, magnitude-limited, of 118 galaxies within the central half degree-are used to examine the structure, kinematics, dynamics, and morphological segregation of the duster. We show that early type galaxies appear to be a relaxed system, while the spiral population eschews the center of the cluster and exhibits both a multimodal velocity distribution and a much larger velocity dispersion than the ellipticals. We propose that the spiral galaxies of A2634 represent a dynamically young cluster population. For the galaxy component of A2634, we find no evidence of significant substructure in the central regions. We also conclude that the adoption of lenient membership criteria that ignore the dynamical complexity of A2634 are unlikely to be responsible for the conflicting results reported on the motion of this cluster with respect to the CMB. The kinematical and dynamical analysis is extended to A2634's close companion, A2666, and the two distant background clusters.
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