Phase-space diagrams for spectroscopically confirmed members and subgroups. Left: galaxies are sized and coloured according to the stellar mass. Measured velocity differences are multiplied with a factor of $\sqrt{3}$, to account for measuring projected velocities (Rhee et al. 2017). Right: phase-space diagram for the subgroups with sizes coded with the estimated halo mass (Table 3). The errorbars on the subgroups show the estimated virial radius in the radial direction, and the uncertainty on the central velocity in the velocity direction. Overlaid: v_esc, NFW calculated as a NFW profile with c_halo = 20.46 shown as a black dashed line, and v_esc, point as a point mass distribution (c_halo → ∞) shown as a black dotted line. The virial region of the core is defined as v_r < v_r, crit and R < R_vir from Sanchis et al. (2004), which is shown with a red shaded area.