Position-velocity plot of H I (in color) with diffuse component subtracted (see text). The black contours show ¹²CO mean antenna temperature between 0.2 and 3 K in steps of 0.5 K. White stars indicate the CH velocity centroids. In the insert, we show the RA range (dashed red lines) within which the PV plot is computed. Negative H I antenna temperature arises from the diffuse component subtraction and should be ignored. For a description of extremely diffuse component subtraction, see Monaci et al. (2022).