Gas column density, temperature, CO optical depth, flux density, cumulative line flux, rotational diagrams, and line-profiles of the ¹²CO P(9), ¹³CO R(4), and C¹⁸O R(6) emissions of the best-fit grid model. The model is shown in red, and the observations in black. Observed line-profiles are displayed in flux units after continuum subtraction with 3σ error bars. The two branches seen in the rotational diagram correspond to the R and P branches of CO ro-vibrational emission. The rightmost panels compare the normalized theoretical line-profiles with the observed composite line-profile of each CO isotopolog with a 1σ error bar.