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The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), a 1.7 m diameter offset Gregorian telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 μm, saw first light in 1995 and operated until 2005. It was the first radio telescope to operate continuously throughout the winter on the Antarctic Plateau. It served as a site testing instrument and prototype for later instruments, as well as executing a wide variety of scientific programs that resulted in six doctoral theses and more than one hundred scientific publications. 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. Multiple submillimeter-wave and Terahertz detector systems were in operation on AST/RO, including heterodyne and bolometric arrays. AST/RO's legacy includes comprehensive submillimeter-wave site testing of the South Pole, spectroscopic studies of 492 GHz and 809 GHz neutral atomic carbon and 460 GHz and 806 GHz carbon monoxide in the Milky Way and Magellanic Clouds, and the first detection of the 1.46 THz [N II] line from a ground-based observatory.

We present the first detection of 12CO (J = 7 → 6) emission in the Magellanic Clouds toward the 30 Doradus region using the Antarctic Sub-millimeter Telescope and Remote Observatory (AST/RO).

A large single-dish submillimeter-wave telescope equipped with a focal plane array containing ~10^4 bolometers and costing about $120M could locate most protogalaxies in the southern sky within a year of operation., 2 pages, 1 figure, for Highlights of Astronomy, ASP Conference Series, Vol 13. 2003 ed. O. Engvold & M. G. Burton

We could observe the Earth as an extra-solar planet, viewing Earthshine on the dark side of the Moon, at the Pole, in winter.

The Antarctic submillimetre Telescope and Remote Observatory (AST/RO), a 1.7 m offset Gregorian, is scheduled for installation at the South Pole in November 1993. It is a collaboration including the Smithsonian Astrophysical Observatory, AT&T Bell Laboratories, Boston University, the University of Illinois, the University of Colorado, and the University of Cologne. Observational tests (Pajot 1990; Dragovan et al 1990) and modeling (Bally 1990) of atmospheric transparency over the Pole indicate that it is the best accessible submillimetre-wave site in the world. The immediate scientific goals are heterodyne spectroscopy of galactic molecular clouds and molecular lines in the earth’s stratosphere at wavelengths near 600 μm. Two early observational programs are a large-scale survey of the CI line at 609 μm and monitoring of the 2.8 mm O3 line arising in the stratosphere. Under the newly-formed Center for Astrophysical Research in Antarctica (centred at Yerkes Observatory), AST/RO will become a general-purpose instrument for the millimetre, sub-millimetre and far-infrared.

AST/RO (Antarctic Submillimeter Telescope and Remote Observatory), a joint project between AT&T Bell Labs, Boston University and the University of Illinois, will place a 1.7-m submillimetre telescope at the South Pole (a high, dry site) in 1992. The highly automated off-axis parabolic telescope will be equipped initially with two channels of 500 GHz (600 μm) heterodyne receivers and AOS spectrometers. A primary goal of the project is a large-scale survey of CI and CO(4-3) line emission from the southern Galaxy and the Magellanic Clouds, in an effort to further the understanding of the warm interstellar medium and star formation in the two galaxies.

M31 is among the few galaxies whose solid angle is more than 100 times the beam area of currently operational millimeter-wave telescopes. Roughly 10% of its area has been mapped in the J=1→0 line of CO with the 7-m telescope at Bell Laboratories. The data lie on the major and minor axes and in a filled 20′ by 15′ field. The average CO emissivity is less than 1/5 that of the Milky Way Galaxy, and the inferred H2 column densities are less than 10% of the HI column densities at the same positions. Thus M31 has a predominantly atomic interstellar medium, whereas our Galaxy seems to have a predominantly molecular interstellar medium. The molecular emission is strongly concentrated in spiral-arm segments, with greater than 25:1 contrast between arm and interarm regions. Overall, the CO emission is well correlated with the HI emission, but shows greater concentration to the spiral arms. There is no evidence for a spatial separation of the HI and CO arms to within our resolution (~1′): all the spiral-arm tracers are spatially coincident. Almost all the gas on the minor axis exhibits non-circular velocities of about 20 km s-1. There are systematic streaming motions as large as 80 km s-1 associated with spiral arms.

The mechanism of spiral structure in galaxies is a puzzle that is only partly understood. Galaxies do not revolve like solid bodies, so the spiral patterns cannot be entirely material in nature. Yet the observable tracers of spiral structure are unquestionably material: young stars, dust and gas. These objects must be organized by a collective, wave phenomenon, the spiral density wave in the disk star population. The density wave is a small (≈ 10%) local increase in the density of stars. The interstellar medium responds to the increased gravitational force by forming Giant Molecular Clouds (GMCs), concentrations of 105M⊙ or more of interstellar matter in a region about 50 pc across. In a sense the GMCs are the spiral arms: in other galaxies, dust, gas and young star populations trace spiral structure; in the solar vicinity, these populations are seen to be associated with GMCs. This paper briefly reviews observational data supporting the hypothesis that spiral structure results from the agglomerative build-up of GMCs from smaller clouds, that this growth occurs preferentially in spiral arms, and that GMCs subsequently self-destruct because of the formation of massive stars.

The major stumbling block in the determination of a rotation curve beyond the solar circle has been the lack of a suitable set of objects with well defined and independently measured distances and velocities which can be observed to large galactocentric radii. Two things have changed this situation. The first was the realization that essentially all local HII regions have associated molecular material. The second was the acquisition of reliable distances to the stars exciting a sizable number of HII regions at large galactocentric radii (Moffat, FitzGerald, and Jackson 1979). Because the velocity of the associated molecular gas can be measured very accurately by means of radio observations of CO, we have been able to overcome the past difficulties and have measured the rotation curve of the Galaxy to a galactocentric distance of 18 kpc.