Top: channel map of ¹³CO near the H ii region in the Caribbean Islands region. The cross in each panel marks the position of the H ii region, G085.051−0.182, reported by Lockman et al. (1996). The central velocity of each channel, in km s ⁻¹, is marked on the top left corner of each map. The blue arrow is the axis of the position–velocity map. Bottom: position–velocity map along the axis shown in the top panel. The grayscale background indicates ¹²CO, black contours indicate ¹³CO, and white contours indicate C ¹⁸O. The lowest contour is 5σ for ¹³CO and 10σ for C ¹⁸O, with the contour interval of 5σ. The cross indicates the rest velocity and the position of the H ii region.