Channel maps of ¹³CO emission in the velocity range −15 to +5 km s⁻¹ with steps of 2 km s⁻¹. The magenta dashed circles indicate H II bubbles from Anderson et al. (2014). the vertical black lines indicate the positions of the broad V-shapes observed in the lv plot in Fig. 8. The labels indicating the various emission features in the maps are the same as in Fig. 4. Some optical H II regions (as in Fig. 1) discussed in the text are also labelled in the top left channel map for reference. For a clearer view of the channel maps, zoomed-in maps towards the central filaments, GM-24 and G352, are presented in Figs. C.1 to C.3.