Combined RGB plot and channel maps for RCW120 and W40. Each panel displays the distinct velocity ranges (blue and red for the high-velocity blue- and redshifted emission, green for the bulk emission) as an RGB plot with contours of ¹²CO(3−2) (RCW120) and ¹³CO(3−2) (W40) emission overlaid. The contour levels are 4 to 39 K km s⁻¹ in steps of 5 K km s⁻¹ for RCW120 and 2 to 26 K km s⁻¹ in steps of 4 K km s⁻¹ for W40. The corresponding CO velocity is given in the upper-right corner. In the first RCW120 panel, the expanding [C II] bubble is approximated by a dotted circle. The exciting stars are indicated with yellow star symbols. Examples of high-velocity blue- and redshifted [C II] gas not associated with the expanding bubble are indicated with blue and red arrows, respectively.