Rotational population diagram of CO based on Table 1. Shown are the level column densities calculated assuming the absorption lines are not saturated (in blue; open circles and filledsquares, respectively) and after the low-velocity component is isolated by fitting Gaussian profiles and corrected by the curve of growth analysis (in orange). An expanded view of the low-J portion is shown in the left panel. The gray line is the best fit LTE population distribution of the two-temperature components of the observation. A summary of the model is given in Table 2.