Computed o-H₂O 1₁₀ –1₀₁ flux as a function of H₂O gas mass. Four different gas kinetic temperatures are shown; 50 K (top left), 100 K (top right), 200 K (bottom left) and 400 K (bottom right). Solid lines show LTE calculations, while each other line corresponds to an electron density; 100 (dashed), 300 (dotted), and 900 cm⁻³ (dash-dotted). The horizontal lines in each plot indicate the 95% line flux upper limit obtained from the data (Sect. 3.1). The solid horizontal line corresponds to using a Gaussian profile, and the dashed line to the spectral profile matching the CO.