Figure 4: Boltzmann plot of D2O rotational levels observed in the supersonic jet at 875 K. The error bars indicate deviations from the average for each data point. The calculated rotational temperatures from the linear fits are 19 ± 2 K for the ground vibrational state (green squares) and 20 ± 6 K for the vibrational state (blue circles). The uncertainties in the temperatures are values.