Extinction map for M 22 in equatorial coordinates (J2000). The small and large circles indicate, respectively, the GC’s center and the area where the program stars (crosses) lie in the GC’s field. The color bar gives the excesses E(B − V) for the extinction map. The zero point is arbitrary and it is calculated by comparison with isochrones (see Alonso-Garcia et al. 2011, 2012, for more details on the techniques and methods used to create this figure). The orientation is different from Fig. 1 (North-East points to the upper right corner).