General results of the t-SNE+HDBSCAN application. Upper-left panel: t-SNE projection for SGB stars in APOGEE DR17. Colours correspond to different groups found by t-SNE+HDBSCAN on the data. Lower-left and middle panels: abundance ratios of α elements to those of the iron group plotted against metallicity using the same colours for each identified group. Right panels (from top to bottom: i): (i) cumulative age distribution for each group; (ii) mean azimuthal velocity (left y-axis and square symbol) and mean dispersion in azimuthal velocity (right y-axis and star symbol) for each group as a function of age; (iii) mean vertical velocity (left y-axis and square symbol) and mean dispersion in vertical velocity (right y-axis and star symbol) for each group as a function of age; (iv) mean metallicity (left y-axis and square symbol) and mean dispersion in metallicity (right y-axis and star symbol) for each group as a function of age. The error bars in the right panels represent the 95% confidence interval of a bootstrap resampling.