Fig. 7a-f. Observed and computed line profiles for Ca I 6439.075 Å (panel a), Fe I 6430.852 Å (panel b) and Fe I 6421.360 Å (panel c). The plusses are the observations and the full lines are the fits. The right column shows the maps from the individual lines in a pseudo-mercator projection. Note that the spectral lines are arranged from top to bottom according to decreasing equivalent width of the main mapping line and thus approximate their depth of formation.