Upper panel: distribution of the sample in the | Z | vs. R plane. The points are colored as in Fig. 2. Two vertical dashed lines delimit the solar region 7 <R< 9 kpc, while a point-dashed horizontal line is drawn at | Z | = 1.2 kpc. Lower panel: normalized generalized histograms (kernel 0.5 kpc) showing the radial distribution of the main GMM data groups (excluding the halo stars; cyan group). They are computed using only stars with | Z | < 1.2 kpc to reduce the effect of undersampled regions far from the Galactic plane.