Double Gaussian fit of the CIV emission line. The rest frame LBT/LUCI continuum-subtracted spectrum is reported in grey, the two Gaussian functions in red and the sum of the two in blue. The larger Gaussian (solid red line; λ ≃ 1541 Å) has a FWHM of ∼9520 km s⁻¹; instead the narrower component (dotted red line; λ ≃ 1549 Å) has a FWHM of ∼1330 km s⁻¹. The intervals for the continuum selection are indicated with dashed green vertical lines.