Spectral Line Picker
The spectral line catalogue used by the OT is the Splatalogue3.1 and the millions of spectral line transitions contained within this can be searched for and selected using the Spectral Line Picker. This appears at various points in the OT where it fulfils different functions: creating spectral windows, overlaying lines in the Visual Spectral Editor and defining rest frequencies. The OT itself contains a useful subset of the whole Splatalogue, but there is also the option to search the whole Splatalogue on-line.
- Transition Filter: Text string for selecting the transitions. Note that quantum numbers are ignored. The description fields can be searched at the same time and this is enabled by default.
- Frequency Filters:
- ALMA Band: To search in the selected ALMA bands.
- Sky Frequency: Search in a certain frequency range. The range can be defined more precisely using the Min and Max fields.
- Receiver/Back End Configuration:
- All lines: Perform no filtering i.e. show all lines.
- Potentially selectable lines: Show lines that might possibly give a valid tuning solution if added to the current setup.
- Lines in defined spws: Only show those lines which fall into the currently defined spectral windows. This is the only option when defining rest frequencies.
- Upper-state Energy: This filter sets the minimum and maximum energy levels of the upper state of the transitions.
- Molecule Filter/Environment: Narrow the candidate molecular transitions by selecting the category of lines to be shown.
- Find More...: Also search the on-line catalogue. The lines found are added to the OT's list of available lines, for the duration of a particular OT session.
- Reset Filters: Reset the filters to the original values.
The ALMA OT Team, 2024 Mar 01