Top panel: FWHM(C IVλ1549) vs. FWHM(Hβ) (full profiles) for the FOS+HE sample. Data points are color-coded according to sample and population: HE Pop. A – blue circles (), HE Pop. B – red squares (), FOS Pop. A – aquamarine circles (), and FOS Pop. B – golden squares (). Best fitting least-square lines (dashed) are shown in blue for all Pop. A and red for all Pop. B. The black dot-dashed line is the equality line. The continuous gray line is the expected FWHM following the correction of Sulentic et al. (2006a, corr). Lower panel: ratio between FWHM C IVλ1549 and FWHM Hβ as a function of FWHM (Hβ).