Hydrogen number densities of the warm absorbers plotted as a function of their ionization parameters. Our results for components 1–5 from the tpho model are shown as stars. The gray shaded region represents the region where the outflow is unable to escape the gravitational potential of the black hole due to n_H > n_esc, while the dashed line indicates the position of (see Sect. 4.4). The red shaded region shows the forbidden regime where the thickness of the outflow exceeds its distance (n_H < n_low). The blue shaded regions indicate the areas where density-sensitive X-ray lines can be utilized to measure densities.