2005AJ....129.1827G

The Cl 1604 supercluster at z∼0.9 is known to contain at least four distinct member clusters, separated in both projection and redshift. In this paper we present deep, multicolor, wide-field imaging of a region spanning ∼45' on a side, corresponding to 21h^–1₇₀Mpc (physical) at the supercluster redshift. We select galaxies whose colors correspond to those of spectroscopically confirmed cluster members in the i' versus r'-i' color-magnitude diagram. Using an adaptive kernel, we generate a map of the projected red galaxy density and identify numerous new candidate clusters that are likely supercluster members. Assuming that all of the density peaks are associated with the supercluster, its transverse size is ∼10h^–1₇₀Mpc, which is still significantly smaller than the nearly 93h^–1₇₀Mpc depth in redshift space.