Average (over regions 110 arcsec wide in radial distance) age, metallicity, [α/Fe], and M/L_V profiles in the B/P bulge region of M 31 (black full lines; see Fig. 3). The black dashed line in the M/L_V plot shows the average (over the same regions) of the M/L_V 20% values. The black dashed line in the age plot shows the 20% percentile of the distribution of values in the bins; the dotted lines in the other plots show the 34 and 84 percentile of the distributions of values in the bins. The straight green (see Fig. 3) line shows the fitted gradient (see Table 2). The blue lines show the composite stellar population model according to Eq. (6) and Table 4, the dotted red and green lines the assumed profiles for the CB and B/P components, respectively. The blue dashed lines show the age and M/L_V profiles obtained using the age values denoted with “20%” in Table 4.