ALMA through the years
The birth of ALMA dates back to the end of the last century. Large millimeter/submillimeter array radio telescopes were studied by astronomers in Europe, North America and Japan and different possible observatories had been discussed. After thorough investigations, it became obvious that the ambitious projects of all of these studies could hardly be realized by a single community.
Consequently, a first memorandum was signed in 1999 by the North American community, represented through the NSF (National Science Foundation), and the European community, represented through ESO (European Organisation for Astronomical Research in the Southern Hemisphere), followed in 2002 by an agreement to construct ALMA on a plateau in Chile.
Thereafter, Japan, through the NAOJ (National Astronomical Observatory of Japan), worked with the other partners to define and formulate its participation in the ALMA project. An official, trilateral agreement between ESO, the NSF, and the National Institutes for Natural Sciences (NINS, Japan) concerning the construction of the enhanced Atacama Large Millimeter / submillimeter Array was signed in September 2004. This agreement was subsequently amended in July 2006.
NAOJ will provide four 12-meter diameter antennas and twelve 7-meter diameter antennas for a compact array (ACA), the ACA correlator and three receiver bands. With the inclusion of the Asian partners, ALMA has become a truly global astronomical facility, involving scientists from four different continents.