Significant correlations between luminosity and the observed UFO properties and energetics. Panel a: L_X versus v_out (upper plot), ξ (middle plot), and N_H (lower plot). Panel b: L_X versus Ṁ_wind (upper plot), ${\dot{E}}_{\mathrm{k}}^{\mathrm{wind}}$ (middle plot), and Ṗ_wind (lower plot). The S23 UFO sub-sample is shown in red circles, T10 in blue diamonds, and C21 in black squares. The solid lines represent the best-fitting linear correlation and the dark and light gray shadowed areas indicate the 68% and 90% confidence bands, respectively. In the legend, we report the best-fit coefficients, logNHP, and the intrinsic scatters for the correlations.