SimLine modeling setup of the C⁺ bubble overlaid on the observed ¹²CO 6 → 5 and [C II] intensities. The panels (¹²CO 6 → 5 on the left and [C II] on the right) show a sketch of the setup for an ideal 3D bubble (note that the calculations are in 1D) in which the different shell regions are indicated. The positions of observed and modeled spectra, shown in Fig. C.2, are indicated by blue squares. The red star marks the exciting O star of the cH IIR.