Dynamically selected populations in the angular momentum-energy plane. The grey points are all the stars that cannot be classified as disc (thick or thin), GSE, or Sequoia. The grey points plus Sequoia, plus GSE, is what can generically be called halo. The units for energy are 10³ × km² s² (actually it is a specific energy, or energy per unit mass) and 10³ × kpc km s⁻¹ for the angular momentum.