Left panel: spatially integrated spectra extracted from the source-plane line data-cubes constructed from the lens model. The error bars are dominated by the uncertainties in the data. The black curve shows the results of fitting 3 Gaussian line profiles: the blue line represents the B component, the green line represents the gas bridge G component, and the red line represents the receding gas R component (Rb+Rr). The line profiles of CO(6–5) and H₂O(2₁₁−2₀₂) are similar, having ∼1.7 times stronger (peak flux) red-shifted emission compared to the blue-shifted emission. This indicates that there is a similar spatial distribution between the CO(6–5) and H₂O(2₁₁−2₀₂) line emission. The asymmetry of the profile suggests an intrinsically complex velocity structure. Right panel: a sketch of the gas-rich major merger, G09v1.97. The source is composite of three major components, a rotating disk to the north that corresponds to the R component of the spectra shown in the left panel or the double-Gaussian component Rb+Rr seen in the image-plane spectrum, while the compact blue galaxy in the south corresponds to B part of the line profile. There is also a dust-rich gas bridge between the two over the component which has weak CO(6–5) and H₂O(2₁₁−2₀₂) emission.