Absolute calibration of millimeter-wavelength spectral lines.
Abstract
A detailed analysis of the chopper-wheel method of calibrating the intensity of a millimeter-wavelength spectral line is presented. Special techniques were used to construct a receiver which eliminates most of the usual calibration difficulties. The zenith atmospheric extinction between 3.5 mm and 2.6 mm wavelength was measured, and teh intensities of six spectral l ines in this range were absolutely calibrated with an estimated uncertainty (1 sigma) of 7 percent. The effects of the antenna power pattern on the corrected antenna temperature T_A* are calculated for several simple models of the source brightness distribution.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- March 1976
- DOI:
- 10.1086/190361
- Bibcode:
- 1976ApJS...30..247U