Atacama Large Millimeter / Submillimeter Array - Taiwan

ALMA IS THE WORLD'S LARGEST, MOST SENSITIVE RADIO TELESCOPE OPERATING AT    MILLIMETER WAVELENGTHS:

The Atacama Large Millimeter/Submillimeter Array (ALMA) is the largest ground based, international astronomical observational facility ever built. It is currently under construction in the Chajnantor area in the Atacama desert in northern Chile. ALMA is designed to cover the wavelength range from 0.3mm to 9mm with an angular resolution of up to 0.004 arcsec. The baseline project consists of the 12-m array of up to 64 12-m telescopes, and the Atacama Compact Array (ACA) of 4 12-m telescopes and 12 7-m telescopes. ALMA will be studying a broad range of exciting science, such as weather patterns on solar system planets, the formation of planets and stars in our galaxy, the motions within active galactic unclei , and the formation of the earliest galaxies at z~10.

Artist's conception of the ALMA antennas in a compact array. Image courtesy of  NRAO/AUT and ESO. ALMA/Chajnantor Video Clip, Backgrounds & Photos ( from ESO Press Release, 10 June 1999)

ALMA IS AN INTERNATIONAL COLLABORATION PROJECT:

ALMA is a partnership of North America, Europe, and Japan in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), on behalf of Europe by ESO, and on behalf of Japan by the National Astronomical Observatory of Japan (NAOJ). The North America and Europe partners are responsible for the construction of the 12-m Array, while Japan is responsible for the construction of ACA.

TAIWANESE PARTICIPATION IN THE ALMA PROJECT:

In September 2005, the Academia Sinica (AS) in Taiwan entered into an agreement with the National Institutes of Natural Sciences (NINS) in Japan in order to join the ALMA project through ALMA-Japan project. Taiwan has also been exploring a possible collaboration with ALMA-NA (North America). Taiwan will contribute to the construction of the array and associated engineering projects. Under collaboration with local industry in Taiwan, Front-End integration center (FEIC) for the Atacama Compact Array (ACA) will be established in Taiwan. All the front-end subsystems for ACA will be assembled and evaluated at FEIC in Taiwan. In addition, ASIAA has been working on the highest frequency (950 GHz) receiver band with ALMA-J, and is also participating in development of the ALMA software in Germany and the US.

HOW ALMA WILL WORK:

ALMA will be composed of 64 high-precision antennas, each 12 metres in diameter. The ALMA antennas can be repositioned, allowing the telescope to work much like the zoom lens on a camera. At its largest, ALMA will be 14 kilometers across. This will allow the telescope to observe fine-scale details of astronomical objects. At its smallest configuration, approximately 150 meters across, ALMA will be able to study the large-scale structures of these same objects. ALMA will function as an interferometer. This means that it will combine the signals from all its antennas (one pair of antennas at a time) to simulate a telescope the size of the distance between the antennas. With 64 antennas, ALMA will generate 2016 individual antenna pairs ("baselines") during the observations. To handle this enormous amount of data, ALMA will rely on a very powerful, specialized computer (a "correlator"), which will perform 16,000 million million (1.6 x 1016) operations per second. Currently, two prototype ALMA antennas are undergoing rigorous testing at the NRAO's Very Large Array site, near Socorro, New Mexico, USA.

ALMA'S UNIQURE CAPABILITIES & RESEARCH TOPICS:

ALMA's ability to detect remarkably faint sub-millimeter and millimeter wavelength emission and to create high-resolution images of the source of that emission gives it capabilities not found in any other astronomical instruments. ALMA will therefore be able to study phenomena previously out of reach to astronomers and astrophysicists, such as: - Galaxies forming billions of years ago "when galaxies were very young", - Map gas and dust in the Milky Way and other galaxies, - Search for planets in other solar systems, - Study star and planet formation, - Investigate ordinary stars, - Analyze ancient stardust, - Analyze gas from an erupting volcano on Jupiter's moon, Io, - Study the origin of the solar wind.

THE EXTRAORDINARY ALMA SITE:

Since atmospheric water vapor absorbs millimeter and (especially) sub-millimeter waves, ALMA must be constructed at a very high altitude in a very dry region of the earth. Extensive tests showed that the sky above the Atacama Desert of Chile has the excellent clarity and stability essential for ALMA. That is why ALMA will be built there, on Llano de Chajnantor at an altitude of 5,000 metres in the Chilean Andes. A series of views of this site, also in high-resolution suitable for reproduction, is available at the Chajnantor Photo Gallery.

TIMELINE FOR ALMA:

May 1998: Start of Phase 1 (Design & Development)
June 1999: U.S./European Memorandum of Understanding for Design & Development
February 2003: Final North American / European Agreement
September 2004: North American, European & Japanese draft agreement
October 2004: Opening of Joint ALMA office, Santiago, Chile
October 2005: Groundbreaking at 5000 m altitude Array Operation Site of ALMA
September 2005: Taiwan joins the ALMA Project through Japan
June 2006: N. American, European, & Japanese Agreement on the Enhanced ALMA
2009: Call for shared-risk early science proposals
2012: ALMA construction complete