Notes. The systemic C IV emission line centers (both of the doublet lines), λ_0,C IV, are constrained to the line center of HeII, which is the systemic redshift, i.e., the fitted line center ratio, is set equal to the rest frame line ratio . The lower index “1” and “2” used in this table indicate the blue and red component of the doublet line, respectively. The blueshifted doublet line center ratio, , is only constrained to the ratio in rest frame, , i.e., the velocity shift of blueshifted doublet is leaving free. The line widths of the doublet are set to be equal to each other in velocity space. Hence, the ratio of the line width in wavelength space, as the direct fitting parameter in this work, is proportional to the ratio of doublet line center in rest frame, . The line flux ratio of the doublet, , is set to be equal to the ratio of its oscillator strength, . Using data from Cashman et al. (2017), we fix the to be approximately 2 for both the C IV and N V doublets. The absorption fit parameters are set to be the same for the doublet.