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Spectral Line

Four panels for each baseband will be visible and up to four spectral windows (spw) can be added to each. Adding a spectral window is done either by selecting spectral lines from the spectral line catalogue or by adding them manually. One of the spectral windows should be selected as that which will set the Representative Frequency. This defaults to the centre of the spectral window, but can be changed at the bottom of the page. This sets the size of the antenna beamsize drawn in the Visual Spatial Editor and is also used to work out the time estimate for the Science Goal. The Spectral Line and Spectral Scan interfaces can not be used with full polarization.

For each baseband, the following buttons are available:

Figure 5.1: The spectral window table for a single baseband. Two spectral windows have been defined, each of which take up half of the available correlator capacity. Note that each has the same spectral resolution (this must be the case) and that the bandwidths are proportional to the assigned fraction. Further note that if there were different spectral averaging factors per spectral window, the spectral resolutions would not appear to be the same, although the bandwidths would still indicate the chosen fraction.
Image SpectralWindows

The spectral window table (Fig. 5.1) has the following columns. Most accept input by being double-clicked.

The value of the Representative Frequency is displayed below the table of spectral windows. Its value will default to the centre of the chosen spectral window, but can be changed to another frequency within that spectral window if the transition of greatest interest is not at the centre. For spectral line setups this is defined in the rest frame of the source. This is so that sources with different velocities end up with the appropriate Representative Frequency in the observed frame.


next up previous contents
Next: Single Continuum Up: Spectral Setup Previous: Spectral Setup Errors   Contents
The ALMA OT Team, 2018 Sep 25