Spectra of Hβ (left panels) and of Mgiiλ2800 (right panels) for spectral types B1 to B1⁺⁺ (from top to bottom). The horizontal scales are in rest frame wavelength [Å] or radial velocity, with the origin set at the rest frame wavelength. The black lines shows the original, continuum-subtracted spectrum, and the dashed magenta line the model with all emission line components. The thick black line is the BC; the thick red line shows the VBC. The green lines trace the Fe ii_opt and Feii_UV contribution, and the gold lines various contributions associated to the NLR (Hβ_NC, [Oiii]λλ4959,5007, and Mgiiλ2800 narrow component when appropriate). Excess emission at λ ≳ 2900 Å visible in this and in the next two figures is likely due to a combination of Fei and Balmer continuum emission.