Position–velocity diagram of the [C II] 158 μm (upper panel) and CO (2–1) (lower panel) emission along an eastwest cut across the bubble at the declination of globule #4 (− 5°44′11.55″). We created this diagram by averaging spectra over a cut of 45″ wide in declination. A model of a half-shell expanding at 13 km s⁻¹ is shown as a curved red dashed line (from Pabst et al. 2019). The bright emission at v_LSR = +8 km s⁻¹ (horizontal red dashed line) corresponds to the background dense molecular cloud and the integral-shape filament.