Histogram distribution and cumulative distribution of FG (red) and SG (blue) RGB stars as a function of the radial distance r. Histograms and cumulative curves from r=0′ and r=3′ were obtained from the HST photometry (upper panel), while those from r∼2′ to r=30′ were obtained from the ground-based photometry (lower panel). We note that the x-scale is different for the two panels and that for the upper panel was extended to 6′ in order to improve the visualization.