An Optical Analysis of the Merging Cluster Abell 3888
  In this paper we present new AAOmega spectroscopy of 254 galaxies within a
30' radius around Abell 3888. We combine these data with the existing redshifts
measured in a one degree radius around the cluster and performed a substructure
analysis. We confirm 71 member galaxies within the core of A3888 and determine
a new average redshift and velocity dispersion for the cluster of 0.1535 +\-
0.0009 and 1181 +\- 197 km/s, respectively. The cluster is elongated along an
East-West axis and we find the core is bimodal along this axis with two
sub-groups of 26 and 41 members detected. Our results suggest that A3888 is a
merging system putting to rest the previous conjecture about the morphological
status of the cluster derived from X-ray observations. In addition to the
results on A3888 we also present six newly detected galaxy over-densities in
the field, three of which we classify as new galaxy clusters.
