Dome C, Antarctica: the best accessible submillimeter site on the Planet?

• Main Authors: J. W. V. Storey, P. G. Calisse, M. C. B. Ashley, M. G. Burton, J. R. Lawrence, T. Travouillon, M. A. Phillips, J. B. Peterson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; South Pole; The Antarctic; Antarc*; Antarctica; South pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.65.1477; http://www.phys.unsw.edu.au/~mgb/Antbib/zermatt2003_paper.pdf

The French-Italian station of Dome Concordia (lat. 76 ° S; long. 123° E; alt. 3,205 m) will be operating winter over since January 2005, offering a new outstanding opportunity for the deployment of instrumentation for submillimeter astronomy. In summer 2003, SUMMIT, a tipper operating at 350 µm, has been deployed at the site. A preliminary analysis of the winter submillimeter opacity data obtained is presented. 1. SUMMIT and the NRAO Submillimeter Tippers The submillimeter tippers were originally developed at NRAO and Carnegie-Mellon University to monitor the sky opacity at submillimeter wavelengths at different remote sites. They have been installed at Atacama (Chile), Mauna Kea (Hawaii, US), and South Pole (Antarctica). A rugged, low power version, designed to operate unattended on the Antarctic Plateau has been developed at the University of New South Wales. It operated originally at Dome C over the summer of 2000–01, gathering the first submillimeter data from this site [2]. The instrument then spent two years at the South Pole, to perform a cross-calibration with the NRAO tipper permanently installed at that site. This calibration demonstrated consistency between the two instruments. The tippers operate at a central frequency of about 350 µm (857 GHz) with a bandwidth of ~108 GHz. A rotating 45º parabolic off-axis mirror allows measurement of the flux received from the atmosphere at different airmasses from 0 to 90 degrees zenith angle. Two black bodies, maintained at different temperatures, allow an absolute calibration of the instrument. The two blackbodies are respectively maintained in thermal contact with the external environment (cold) and the inside of the supporting module AASTINO (warm), kept warm by the heat generated by the electrical power generator. A radome with a transmission of 78–80 % protects the system from the atmospheric agents. The beam from the sky (or from the blackbodies) is directed through a chopper, and then to a blocking filter, to an 857 GHz mesh filter and finally to a Barnes ...