I have just been reading the new paper and they are relying on the centriod of the spectral line to distinguish PH3 from SO2 in the 0.3 k/s range. While I feel sure they will have corrected for the Earths velocity as that would be standard for stellar work, I can’t find any reference to correction for the motion of Venus. Does anyone know if this was done.
Also the high wind speed on Venus could shift the line if it did not average out in the measurement.
Regards Andrew