Emission intensity grids of CO(J = 1–0) and ¹³CO(J = 1–0) transitions for the 1D-PDR models. The emission of the models in the grid correspond to an A_V = 10 mag, which amounts to a column density of H, N_H ~ 10²² cm^-2 at solar metallicity. The intensities were computed using the RADEX LVG code. A line-width of 1 km s^-1 was used. No mechanical heating is added for the models in this grid. This is used as a reference grid for the ones in which Γ_mech is introduced (see Fig. 8).