Top panel: 2D number density of a sample of giants in Gaia DR3 cross-matched with APOGEE DR17 that spanned a Galactocentric range of 4–16 kpc (see text for details). The red dashed lines delimit the thick-disc, bridge-, low-α regions used to derive the kinematic properties in Table 2, while the excluded region for this derivation is shaded red. Middle panel: 2D number density of star disc particles, as identified by GMM, in the [Mg/Fe] vs [Fe/H] plane. Green, blue and purple mark the contours containing 90% of the high-α, bridge and low-α disc stars, respectively. Bottom panel: mean age distribution of disc stars in the same plane, with the black contour enclosing the region containing 90% of the star particles in the disc. The last two panels show disc star particles at z ∼ 0.1.