The antarctic submillimeter telescope and remote observatory (AST/RO)

The Antarctic Submillimeter Telescope and Remote Observatory, a 1.7 m diameter telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 μm, was installed at the South Pole during the 1994-1995 austral summer. The telescope operates continuously through the austral winter and is being used primarily for spectroscopic studies of neutral atomic carbon and carbon monoxide in the interstellar medium of the Milky Way and the Magellanic Clouds. The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky. Especially significant are the exceptionally low values of sky noise found at this site, a result of the small water vapor content of the atmosphere. Four heterodyne receivers, an array receiver, three acousto-optical spectrometers, and an array spectrometer are currently installed. A Fabry-Perot spectrometer using a bolometric array and a terahertz receiver are in development. Telescope pointing, focus, and calibration methods as well as the unique working environment and logistical requirements of the South Pole are described.