Gaussian model fit to imaging of the 380 GHz H₂O line integrated line intensity. Left to right: the data; the model on the same colour scale as the data; and the residuals (data–model) in units of σ, where σ is the rms noise in the data. The Gaussian model components are fixed to the size of the synthesized beam (PSF) and their positions are fixed to the image positions in the continuum emission. The component flux densities are initially allowed to optimize, but afterwards are fixed to the continuum flux ratios reported by Stacey & McKean (2018) relative to the optimized flux density of image A1. Residuals of this model fit show surface brightness features around image A2 at the 4σ level.