Zoom-ins on the isolated H₂ ¹⁸O lines, highlighted by the red vertical line. A simple H₂ ¹⁸O slab model (T = 350 K, log₁₀ (N) = 17.66, and R_em = 1.0 au) is shown in red, whereas the best models of H₂O (three component fit accounting for both the radial and vertical temperature gradient) and OH are shown in blue and magenta, respectively. For each transition, we have listed the upper level energies and Einstein-A coefficients.