Top: spectral energy distribution of selected models, showing a WO star with T_eff ≃ 154   000  K (our 32 M_⊙ rotating mode; cyan), a WNL star of spectral type WN10–11 with T_eff ≃ 26   800  K (28 M_⊙ rotating model; blue), and an LBV with T_eff ≃ 20   000  K (20 M_⊙ rotating model; green ). We stress that we do not compute model spectra of RSG and YHGs in this paper. To illustrate the SED of these objects, we also overplot MARCS model spectra of a RSG with T_eff = 3600  K and luminosity scaled to L_⋆ = 1.2 × 10⁵  L_⊙ (red), and of a YHG with T_eff = 5250  K and luminosity scaled to L_⋆ = 1.5 × 10⁵  L_⊙ (yellow). All fluxes have been arbitrarily scaled to a distance of 1 kpc. The upper inset shows the normalized bandpasses of the UBVRIJHK_S filters. Bottom: schematic illustration of the interior structure of the SN progenitors for which spectra are shown in the upper panel. We show the Lagrangian mass coordinate of the progenitor in the y axis and the extension of the layers for different chemical elements (H, He, metals) and the baryonic remnant mass (computed as in Hirschi et al. 2005). The radius of selected shells is indicated on the left side of each subpanel, while the spectral type, SN type, and initial mass of the progenitors are indicated immediately above the interior structure. The chemical abundances (by mass) are color-coded in blue (H), red (He), and gray (metals).