The Harvard-Smithsonian Center for Astrophysics (CfA) has been selected by the National Science Foundation as recipient of a 12-meter (39-foot) radio antenna designed for submillimeter-wavelength astronomy. The ALMA Vertex Prototype Antenna was one of three antennas built as prototypes for the Atacama Large Millimeter Array (ALMA), a 66-dish radio observatory currently being constructed in Chile.

The CfA will operate the antenna in collaboration with the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan. This continues the long-standing and fruitful partnership between the CfA and ASIAA, established with the construction and operation of the Submillimeter Array (SMA) on Mauna Kea, Hawaii.

The CfA is a world leader in the technology for building receivers at submillimeter wavelengths - a little-explored region of the electromagnetic spectrum between visible light and radio waves. With submillimeter antennas, astronomers can study diverse cosmic environments like cold interstellar gas clouds, dusty star-forming regions, and the cores of giant elliptical galaxies.

The prototype antenna will link with other submillimeter observatories like the SMA to provide an extremely sharp, high-resolution look at targets of interest, in a process known as Very Long Baseline Interferometry. It will also conduct single-dish observations.

"This antenna will operate as a pathfinder for the SMA and other interferometers like CARMA and the Plateau de Bure, and will also act as a test-bed for potential ALMA instrument development at the CfA," said SMA director Ray Blundell.

The antenna will be moved to a new location that hasn't been selected yet. Submillimeter astronomy requires a site with an exceptionally dry atmosphere overhead, which is usually obtained at high-altitude locations with prevailing cold temperatures. For this reason, the partners are considering an NSF site in Greenland known as Summit Station.

The NSF requested written proposals for the disposition of the antenna. Three proposals were received and evaluated, including the one from CfA/ASIAA that was ultimately selected.