ALMA plus total-power spectrum around 345.8 GHz averaged over the observed field-of-view. The black histogram shows the spectrum centered at the frequency of the CO J = 3–2 line (LSR velocity scale shown in the upper horizontal axis). The green spectra (and lower velocity axes) show the same for the SO 8₉–7₈ and H¹³CN J = 4–3 lines, both dominantly emitted from the CND in the velocity range |v_LSR| < 150 km s⁻¹ (blanked out for CO). In addition to this standard velocity range, CO shows higher positive and negative velocity emission components: EPVG, HPVG, and HNVG (defined in the text) in magenta, red, and blue respectively. Owing to the similar spatial distribution of the SO and H¹³CN line emission, the CO EPVG features can be easily distinguished from the blue-shifted H¹³CN J = 4–3 emission in the images (see text).