Spatial distribution of cluster members. The local number density is color coded as indicated by the bar at the right side of the plot. Coordinates are in arcmin with respect to the position of the BCG, see Table 1. Galaxies belonging to Regions (a), (b), (c), which are defined in Sect. 3.2.2, are those inside the red, blue, and purple solid lines, respectively. Galaxies belonging to Region (d) are the outer points.