Flux density, cumulative line flux, rotational diagrams, and the line-profiles of the ¹²CO P(9), ¹³CO R(4), and C¹⁸O R(6) emission, for the model with the best combined fit to the rotational diagrams and line-profiles, extrapolating the surface density and temperature profile down to 0.1 AU. The model is shown in red and the observations in black. The 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.