Extended Data Fig. 6: HDO flux measurement using the shifted spectra.
From: Pristine ices in a planet-forming disk revealed by heavy water
The lines blended with the HDO line are subtracted by extracting the line profile of the clean, low frequency side of the blend (blue shaded region), mirroring this in the frequency of the line and subtracting. The top panel shows the model for the CH3OCHO in blue. In the middle panel, this model is subtracted from the data (black) and the new model for the 13CH3CHO is shown in blue. The HDO line is indicated with the red vertical line in the bottom panel.
