WFI B-band imaging. Overlaid circles in blue, red and green denote cluster galaxies with spectroscopic follow-up data that have clustercentric velocities toward the observer greater than 1000 km s^-1, away from the observer greater than 1000 km s^-1, and smaller than 1000 km s^-1, respectively. The radii of these circles are proportional to . The black cross denotes the X-ray flux-weighted centroid and the black dashed circle denotes .