CO(3–2) and CO(2–1) spectral lines toward DarkPK and NE bar. The CO(3–2) spectra are shown in red and the CO(2–1) spectra are in black. The CO spectral lines were extracted at the positions A, B, C, D, E, and F in the DarkPK and NE bar shown by crosses in Figs. 3 and 4, respectively. The integrated CO emission in both transitions was determined using the zeroth-moment within the velocity range shown in the vertical dotted lines. The derived ratio, R₃₂, is shown in the right upper corner of each panel.