Phase-space plot showing the N_H and U_H solutions for the DESI sample (colored Xs) and the VLT sample of Xu et al. (2019) (black plus signs). The colored lines and associated shaded regions indicate the N_ion constraints (measurements and errors, respectively) used to derive the N_H and U_H solutions for the outflow detected in J1426+3151. The phase-space solution with minimized χ² is shown as an orange cross surrounded by a black eclipse indicating the 1σ error.