VoigtFit models in velocity space. The normalised spectra, shown in blue with 3σ error bars, display the regions in the vicinity of the absorption lines; the best-fit models are overlaid in red. Carbon, nitrogen and silicon lines are fitted simultaneously, with two kinematic components; the vertical lines identify the velocity centroids for each kinematic component. For the doublets, the reported velocities are calculated with respect to the systemic of the blue line of the doublet; the kinematic components associated with the blue transitions are in orange, those of the red transitions are in purple. The narrow top panels show the best-fit residuals, with 3σ confidence intervals. Emission line contributions were removed prior to the VoigtFit modelling.