Distributions of HVSs in three sections of phase space in QUMOND with γ = 1.0 (blue dots) and Newtonian gravity with a prolate (q_y = 1, q_z = 1.1) dark matter halo (red dots). Left, middle, and right panels: r − v_r, z − v_z, and r − v_θ sections, respectively. Here, r is the galactocentric distance, z is the vertical coordinate, and v_r, v_z, v_θ are the radial, vertical, and latitudinal components of the velocity, respectively.