ALMA – the Atacama large millimeter array Original Research Article

The Atacama Large Millimeter Array (ALMA) is a major ground-based telescope for millimeter and submillimeter astronomy to be realized during this decade. It is comprised of 64 antennas of 12 m diameter, each of which is equipped with receivers in ten frequency bands that cover the atmospheric windows from 30 to 950 GHz. All the antennas may be moved on a specially-designed antenna transporter so that the antenna array may be reconfigured: At the extremes, the antennas may all be grouped together in an area 150 m in diameter to provide arcsecond angular resolution, or they may be distributed over an area 14 km in extent to provide an angular resolution as high as 10 milli-arcsec. ALMA will be located in the Chilean Andes east of the Atacama Desert at an elevation of 5000 m above sea level. The ALMA Project is a joint venture of the European Southern Observatory and the U.S. National Science Foundation acting in partnership with the National Research Council of Canada. Interim science operations are expected to begin in 2007 with completion of ALMA scheduled for 2011.