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ALMA: A new giant radio telescope for European astronomers

  • The new ALMA radio telescope is now fully operational. It has been inaugurated on 13 March 2013 in the Chilean Andes. The Atacama Large Millimeter/submillimeter Array (ALMA) is a partnership between Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is the largest ground-based astronomical observatory in existence. It is so huge that no single country could have afforded such an astronomical tool alone. © ALMA (ESO/NAOJ/NRAO)
  • The array of ALMA antennas is located in the Chilean Andes, on the Chajnantor Plateau, near the border with Bolivia and Argentina, at an altitude of 5000 metres above sea level. © ALMA (ESO/NAOJ/NRAO)
  • Besides ALMA, ESO, the European Southern Observatory, operates two other world-class observing sites in the Atacama Desert region of Chile: La Silla and Paranal, which is home to the Very Large Telescope (VLT), the largest optical instrument dedicated to astronomy in the world. The headquarters of the European organisation is located near Munich in Germany. © ALMA (ESO/NAOJ/NRAO)
  • Fifty-four 12-metre and twelve smaller 7-metre dish antennas of the ALMA array work together as a single telescope. Each antenna collects radiation coming from space and focuses it onto a receiver. The 66 ALMA antennas can be arranged in different configurations, where the maximum distance between antennas can vary from 150 metres to 16 kilometres. © ALMA (ESO/NAOJ/NRAO)
  • The signals from the antennas are brought together and processed by a specialised supercomputer. The ALMA Array Operations Site, at an altitude of 5000 metres in the Chilean Andes, houses the ALMA antennas and the correlator, the fastest data processing system ever used at an astronomical site. © ALMA (ESO/NAOJ/NRAO)
  • When working at the ALMA Array Operations Site, some safety rules have to be observed. At that altitude, the level of oxygen in the air is halved compared to sea level. Often, technicians have to carry an additional oxygen supply. © ALMA (ESO/NAOJ/NRAO)
  • The ‘base camp’ of the ALMA array, the ALMA Operations Support Facility (OSF), is located some 28 kilometers away, at a much lower altitude of 2900 metres, in the Atacama Desert. This is where the offices, laboratories and telescope control room are located, as well as the site where the antennas are assembled and tested before being taken to their final destination on the Chajnantor Plateau. © ALMA (ESO/NAOJ/NRAO)
  • Two huge dedicated trucks convey the antenna from the base camp to the Chajnantor Plateau. The twin vehicles are 20 metres long, 10 metres wide and 6 metres high, and each has 28 tyres. Empty, each vehicle weighs 130 tonnes. © ALMA (ESO/NAOJ/NRAO)
  • The ALMA radio telescope studies light from some of the coldest objects in the Universe. This light has wavelengths of around a millimetre, between infrared light and radio waves. For astrophysicists, ALMA opens a window on the ‘cold’ universe like early galaxies, clouds of gas and dust where stars and planetary systems are born, or even the chemistry of the interstellar medium. On this picture, one can see a spiral structure of matter surrounding the R. Sculptoris star.© ALMA (ESO/NAOJ/NRAO)
  • ALMA is built in the high Andes because millimetre and submillimetre radiation are heavily absorbed by water vapour in the Earth's atmosphere. Telescopes for this kind of astronomy must therefore be built on high, dry sites, such as the 5000 metre high plateau at Chajnantor, one of the highest and driest astronomical observatory sites on Earth. © ALMA (ESO/NAOJ/NRAO)