Upper panels: comparison of models’ spectra with and without X-rays (dashed red and solid blue curves, respectively). Middle panel: contribution of Fe III, C IV, and N V for the wind acceleration (black, green, and blue lines, respectively). The lines with thick (thin) crosses indicate the model with (without) X-rays. Lower panel: population number of N V and CIV following the same color and symbol code as the middle panel. in the middle and lower panels, the dashed blue line indicates the photosphere (R₂/₃) and the solid gray line indicates the critical radius (R_clit). The onset of X-rays (R_X) is represented by the dashed brown line.