For the PHANGS-eCMZ ALMA imaging process, we encountered an issue with some galaxy centers where there is a mismatch in the spectral coverage between the TP data (obtained from v4_singledish_phangsalma) and the interferometric data.
What's the issue:
For instance, in the case of NGC 1566, the TP spectral range spans from 827 to 1759 km/s. This window is not centered on the systemic velocity (set at 1504km/s). As a result, the current phangs pipeline implements a symmetric window (in the case of 1566 it's +-350km/s), which means one side of the TP spectrum is cut off, while the other side does not have any data. Currently, we had to manually lower the width to ensure the resulting window centered on 1504km/s does not extend beyond the TP range (resulting in a quite narrow cube).
Possible Solution:
Ideally, there could be a step before initiating the sdintimaging process that determines channel overlaps of the TP and INT data. It would then adjust the minimum and maximum channel (i.e. allowing for a window not symmetrical centered on the velocity given in the key file) to ensure TP spectral coverage for each channel.
For the PHANGS-eCMZ ALMA imaging process, we encountered an issue with some galaxy centers where there is a mismatch in the spectral coverage between the TP data (obtained from v4_singledish_phangsalma) and the interferometric data.
What's the issue:
For instance, in the case of NGC 1566, the TP spectral range spans from 827 to 1759 km/s. This window is not centered on the systemic velocity (set at 1504km/s). As a result, the current phangs pipeline implements a symmetric window (in the case of 1566 it's +-350km/s), which means one side of the TP spectrum is cut off, while the other side does not have any data. Currently, we had to manually lower the width to ensure the resulting window centered on 1504km/s does not extend beyond the TP range (resulting in a quite narrow cube).
Possible Solution:
Ideally, there could be a step before initiating the sdintimaging process that determines channel overlaps of the TP and INT data. It would then adjust the minimum and maximum channel (i.e. allowing for a window not symmetrical centered on the velocity given in the key file) to ensure TP spectral coverage for each channel.