Selected transitions of C₆H₅CN among the 49 lines (see Table B.1) used to produce the spectrally stacked map of benzonitrile at each position of the map. The spectra shown here correspond to the central position. The transition quantum numbers are indicated in blue in the top left corner of each panel. Each line arises from the individual maps with S_grid = 20″ and T_rad = 20″. Each line spectrum was multiplied by the factor f (shown in black in each panel) to scale its intensity to that of the strongest one (the 13_0, 13-12_0, 12 transition). The noise of each spectra, after multiplication by f, is shown in violet (σ; in mK). It is used to weight the data during stacking of all the lines at each position of the map (see text). The vertical dashed red lines in each panel indicate the local standard of rest velocity of 5.86 km s⁻¹. The spectra of the resulting stacked data at different positions of the map are shown in Fig. 1.