Isodensity contour levels for sources classified as stellar on both Z and J tiles, i.e. catalog A. Contours are plotted so that, going toward the inner regions, each contour has a 40% higher density with respect to the previous one. The outermost contour has a density of 0.23 × 10⁵ stars/deg²; the next has a density of 0.32 × 10⁵ stars/deg² and so on. The vertical lines indicate the regions along the minor axis in which the profiles in Fig. 14 are computed.