Left panel: decomposition of the continuum-subtracted spectra calculated with DustEM for a radial field intensity that is consistent with what is expected for HD 100546. All the spectra are normalised to the continuum at a distance of 0.2′′. Right panel: correlation between intensities in bands at 3.4, 3.43, 3.46, 3.52, 3.56 μm and the band at 3.3 μm, underlined by those calculated for pixels of HD 100546 that were previously shown in Fig. 4.