Spatial distribution of the 92 cluster members, each marked by a circle. The BCGN(NW) is taken as the cluster center. Upper panel: the cluster velocity field: the larger the circle, the larger the galaxy velocity. Lower panel: the result of the (modified) DS-test: the larger the circle, the larger the deviation δ_s,i of the local velocity dispersion from the global velocity dispersion. Thin/blue and thick/red circles show where the local velocity dispersion is lower or higher than the global value. The two large green squares indicate the positions of the two BCGs.