Sample emission profiles. The species and transitions shown are indicated in the legends. For CH₃OH and CH₂NH, the approximate frequencies are given instead of quantum numbers. We could not assign unique quantum numbers to these features because they are blends of components that arise from transitions of different energy levels or species of different symmetry (e.g. E and A-type methanol). The shaded areas shown in the top panels mark the positions of interstellar features for which HCN and CO spectra were corrected. Some transitions have hyperfine splitting which, however, is insignificant compared to the total line width. For better presentation, some spectra were smoothed and scaled in intensity, as indicated in the legends.