Science Objectives

Science Objectives

Atacama Large Millimeter/submillimeter Array (ALMA)

The Atacama Large Millimeter/submillimeter Array (ALMA) will be the premier telescope in the world for studying millimeter- and submillimeter-wavelength light emitted by the universe. It is under construction in a high-altitude region of northern Chile and, when completed early next decade, will combine an array of up to 64 12-meter-diameter antennas with an additional compact array supplied by Japan.

ALMA will be a truly transformational instrument for studying the cool universe-the relic radiation of the Big Bang and the molecular gas and dust that constitute the very building blocks of stars, planetary systems, galaxies, and life itself. This material typically has temperatures of 3 K to 100 K, resulting in spectral-energy distributions peaking at submillimeter to far-infrared wavelengths. Most of the electromagnetic energy in the Universe lies in two thermal components-the cosmic background and the far-infrared background-within the ALMA wavelength range l = 1 cm to 0.3 mm (30-950 GHz). Indeed, the peak of the spectral-energy distribution for dusty objects in the distant universe is redshifted entirely to submillimeter wavelengths.

NRAO leads the North American component of the international ALMA partnership, whose contributions to ALMA include:

  • The North American ALMA Science Center in Charlottesville, Virginia, ALMA "headquarters" for North America
  • Receiver cartridges for ALMA bands 3 and 6
  • An ALMA "Front End Integration Center" in Charlottesville, Virginia where receiver cartridges from around the world are integrated into large cabinets that are then shipped to Chile for installation into antennas
  • Twenty-five 12-meter antennas
  • ALMA's photonic local oscillator
  • Digital electronics for transmitting signals from the antennas
  • The correlator for the extended array
  • The Array Operations Site (AOS) technical building, second highest steel frame building in the world
  • Road and power distribution to the AOS
  • A variety of scientific tools

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of East Asia, Europe and North America in cooperation with the Republic of Chile. ALMA is funded in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan, in Europe by the European Southern Observatory (ESO) and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC). ALMA construction and operations are led on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ), on behalf of Europe by ESO and on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI).

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The NSF National Radio Astronomy Observatory and NSF Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NSF NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NSF NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NSF NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NSF NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

The U.S. National Science Foundation (U.S. NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."

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