Absolute value of the line-of-sight velocity v relative to the cluster mean velocity as a function of the cluster-centric distance in Mpc (small black plus signs). Filled blue squares are the standard deviations of the line-of-sight velocity in bins of cluster-centric radii where the horizontal bars indicate the bin width and vertical bars the standard error of the standard deviation estimator following Ahn & Fessler (2003). The other vertical lines mark the core radius (dotted) and the virial radius R_vir, 200 (dashed).