Modified wind momentum as function of luminosity and metallicity, as in Figure 4, but now fit with Equation (9) to the three samples, instead of separate linear fits for each sample. The dashed magenta lines and pink shaded regions indicate the best fit and the 1σ confidence interval, respectively. Equation (9) has been evaluated at Z = 1.0, 0.5, and 0.2 Z_⊙. The points with a red border are unreliable fits that are likely not representative of their physical properties; these are not included in the fit.