Institute for radio astronomy in the millimeter range
The Institute for Radio Astronomy in the Millimeter Range (IRAM) is an international radio observatory.
IRAM was founded in 1979 and is operated in German-French-Spanish cooperation. The supporting organizations are the Max Planck Society (MPG), the French Center national de la recherche scientifique (CNRS) and the Spanish Instituto Geográfico Nacional (IGN). IRAM operates two radio astronomy observatories , a 30 m telescope in Spain and an interferometer in France. Both are located on mountains with an altitude of over 2500 m, where the permeability of the earth's atmosphere for radio waves of 1 to 3 mm wavelength is better than at lower altitudes.
30 m telescope on the Pico del Veleta
This single telescope with a reflector diameter of 30 m is located at an altitude of 2920 m near the Pico del Veleta in the Sierra Nevada in southern Spain, about 50 km southeast of Granada . From the 1980s to the full commissioning of the Large Millimeter Telescope in 2018, it was the world's largest radio telescope for the wavelength range from 4 mm down to 1 mm (corresponding to a frequency range from 72 to 300 GHz). It is considered to be one of the most sensitive radio telescopes in the world for measurements at shorter millimeter wavelengths.
It is part of the Event Horizon Telescope project and was one of the telescopes of the worldwide network of eight radio telescopes, with which in 2017 (published in April 2019) the first direct images of a black hole (the supermassive black hole in M87 ) were obtained.
NOEMA millimeter interferometer on the Plateau de Bure
On the summit level of the 2550 m high Plateau de Bure , in Saint-Etienne-en-Dévoluy near Gap in the French Alps, there has been a radio interferometer since 1988 consisting of antennas that can be moved on tracks, each with a diameter of 15 m. They are used for observations with high angular resolution at wavelengths of 1, 2 and 3 mm. With the greatest distances between the antennas of currently 760 m, an angular resolution of up to 0.4 arc seconds is achieved.
Originally there were 6 antennas. As of 2018 and 2020, their number has risen to 10. Since the beginning of an expansion from 6 to 12 antennas with further planned changes, the interferometer NOrthern Extended Millimeter Array is called NOEMA.
The antennas are each bowl-shaped, can be swiveled and rotated and are typically all aligned in the same direction in the sky.
The tracks on which the bases of the telescopes can be moved have about 6 m center-to-center distance between the rails. The longer track runs roughly west-eastward (towards half past four). At about 30% of its length, another main track branches off to the left to the north at an angle of about 80 °. On a section of about 100 m, up to the junction to the right to the hangar, a parallel track allows maneuvering here, as well as two very short track stumps that lead at right angles from the long track approximately northwards. The entrance of an antenna takes place on the west side of the hangar, where gates for a cross-shaped opening can be pushed open. At least one antenna in the hangar can be serviced and protected from the weather.
2 bulldozers are used to extend the tracks .
Currently the antennas can be moved to a maximum distance of 760 m. After expanding the track, 1.7 km should be achieved. The number of antennas is expected to increase to 12 by 2024.
Cable car
The main entrance is a non-public gondola lift, for example from the north-east.
On July 1, 1999 , a gondola fell 80 m deep, killing all 20 passengers, researchers, technicians, construction and cleaning personnel, all from France.
Institute in Talorten
Institute facilities in Saint-Martin-d'Hères near Grenoble (France, headquarters) and Granada (Spain) are used for technical development and support, administration and scientific use.
Web links
Individual evidence
- ↑ Satellite view google.com/maps, accessed July 12, 2020.
- ↑ Radio telescopes: Radio view into space with ten telescopes astronews.com, September 20, 2018, accessed July 12, 2020.
- ↑ Image gallery iram-institute.org, accessed July 12, 2020.
- ↑ Cable car kills 20 people welt.de, July 2, 1999, accessed July 12, 2020.
Map with all coordinates: