Top panel: integrated line intensities of ¹²CO observationsfrom J = 5−4 to J = 13−12 and J = 19–18 (black squares) and ¹³CO observationsfrom J = 5−4 to J = 13−12 (black triangles) are plotted against the upper energy levels of the transitions. The colored lines are the different RADEX fits for different hydrogen densities (n_H): 10⁵ (red), 10⁶ (blue), and 10⁷ (green).The results of the fits are shown in Table 2. Bottom panels: optical depth plotted against the upper level energy for the best fits for each hydrogen density show in the top figure.