Atacama Pathfinder EXperiment APEX
APEX-1 (230 GHz)
MPIfR Bonn   ESO   Onsala Space Observatory
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Sideband response

Ideally the intensities obtained for a line should be independent of the sideband to which the receiver is tuned during the observations. Deviations from this could indicate problems in the receiver, in the calibrator software, or in the atmospheric model used for calibration.

In order to detect such problems and to optimize the calibration stability, we monitor for several sources some lines over the frequency band, which are regularly observed in USB and LSB tunings.

Monitoring results

The following table gives some information for the 2 lines we currently monitor this way.

Line Frequency [GHz] Atmosphere Time variation
12CO(2-1)
230.538000
CS(5-4)
244.935644