Mg IIλλ2795,2802 Å lines (black solid line) and best-fit model (red solid line). Each line is fit with one Gaussian component to take into account the emission (green dot-dashed line) and one Gaussian component to take into account the absorption (blue dashed line). The residuals of the fit are normalized and plotted below the spectrum (black dot-dashed line). The vertical dashed lines mark the restframe wavelength of the fitted emission lines.