Heat map illustrates similarity of the three clusters based on the distributions of J_r, J_z, and [Fe/H]. The rightmost panel shows the distributions of the three clusters in the J_r/J_total–|J_ϕ|/J_total plane, with the median, 16th percentile, and 84th percentile of [Fe/H] for each cluster indicated in the legend. Cluster 0 has a wide span in the plane and could potentially be clustered into smaller groups when additional quantities are considered. Cluster 1 is the most metal-poor and is supported by both radial and rotational motion. Cluster 2 is the least metal-poor and is mainly supported by rotational motion.