Spectra of CO J = 1–0 at the positions of C1b (bottom) and Cl2 (middle) for 0.5 and 1 km s⁻¹ channel width. The green lines show Gaussian fits to marginal detections with the highest integrated signal-to-noise emission. The velocities of the Gaussian peaks are indicated by green vertical dashed lines. The red dotted line shows the corresponding J = 2–1 spectra. The horizontal blue lines at the bottom of each panel indicate the expected velocity range (the Cl2 line is offset by more than 20 km s⁻¹ from the velocity of the HI peak). The top panel shows the CO J = 1–0 stacked spectra of four adjacent positions in Clump1 (C1a, C1b, C1an, C1se). The Gaussian fit to the narrow negative dip (see text) is shown by the continuous green line.