Column-normalised (by sum) 2D histogram of stars in the [M/H]−v_ϕ plane for APOGEE DR 17 giants (with the same high- and low-α separation as shown in Figure 1) for all the stars (right), high-α selection (left), and low-α selection (middle). The running median track is shown as dashed black line and the 16th and 84th percentile tracks are shown as black lines in all panels. The median, 16th and 84th percentile tracks for our Gaia XP sample are shown in grey for comparison. The tracks between Gaia XP and APOGEE samples show remarkable resemblance in high-α and small differences for low-α and all stars due to lower contamination in low-α selection in APOGEE (see Appendix A).