HEGRA , which stands for H igh- E nergy- G amma-Ray A stronomy, was an atmospheric Cherenkov telescope for Gamma-ray astronomy . With its various types of detectors, HEGRA took data between 1987 and 2002, at which point it was dismantled in order to build its successor, MAGIC , at the same site.
15-847: It was located at Roque de los Muchachos Observatory on La Palma at a height of 2200 m above sea level. It was operated by an international collaboration of research institutes and universities, such as the Max Planck Institute for Physics in Munich, the Universidad Complutense de Madrid , the German Max Planck Institute for Nuclear Physics , the University of Wuppertal , the IFKKI in Kiel or
30-763: Is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands , Spain. The observatory site is operated by the Instituto de Astrofísica de Canarias , based on nearby Tenerife . ORM is part of the European Northern Observatory . The seeing statistics at ORM make it the second-best location for optical and infrared astronomy in the Northern Hemisphere , after Mauna Kea Observatory , Hawaii . The site also has some of
45-782: The Galileo National Telescope opened in 1998 and the Gran Telescopio Canarias opened in 2006, with its full aperture in 2009. A fire on the mountainside in 1997 damaged one of the gamma-ray telescopes, but subsequent fires in September 2005 and August 2009 did no serious damage to either the buildings or the telescopes. In 2016, the Instituto de Astrofísica de Canarias and Cherenkov Telescope Array Observatory signed an agreement to host Cherenkov Telescope Array ’s northern hemisphere array at
60-640: The University of Hamburg . It consisted of several detector types for observing secondary particles from particle cascades in the atmosphere. The particle cascades detected by HEGRA were produced by cosmic ray particles in the energy range of 10 eV to 10 eV. The detectors with the lowest energy threshold were the atmospheric Cherenkov telescopes with "cameras" of photomultiplier tubes. They were sensitive to showers above 10 eV (1 TeV) but had to look towards possible sources and could be operated only during clear, moonless nights. They detected Cherenkov light from relativistic secondary particles in
75-707: The ORM. In 2016, the observatory was announced as the second-choice location for the Thirty Meter Telescope , in the event that the Mauna Kea site is not feasible. The Spanish island is host to the premiere collection of telescopes and observatories from around the World, for the northern hemisphere excluding the Hawaiian islands which has a different mix of telescopes. The 10.4 meter Grand Telescope Canarias
90-702: The Spanish island hosting many telescopes from Britain, The Netherlands, Spain, and other countries. The island provided better seeing conditions for the telescopes that had been moved to Herstmonceux by the Royal Greenwich Observatory , including the 98 inch aperture Isaac Newton Telescope (the largest reflector in Europe at that time). When it was moved to the island it was upgraded to a 100-inch (2.54 meter), and many even larger telescopes from various nations would be hosted there. The building of
105-459: The air showers. The field of view was about 4.6°. There were a total of six of these telescopes in operation. They were dismantled in September 2002. The reflectors of the telescope is 3.9 meter in diameter and consisted of 30 spherical mirrors. The area of the reflector is 5 m. Another detector type for Cherenkov light was AIROBICC ( AIR shower O bservation B y angle I ntegrating C herenkov C ounters) with one large photomultiplier looking at
120-547: The instrument was the detection of the most energetic photons observed from an extragalactic object, at 16 TeV , originating from Markarian 501 (Mrk 501). It was shut down in 2002 in order to build the follow-up telescope MAGIC at the same site. A direct successor to the stereoscopic system of Cherenkov telescopes is the HESS experiment. Roque de los Muchachos Observatory Roque de los Muchachos Observatory ( Spanish : Observatorio del Roque de los Muchachos , ORM )
135-670: The most extensive astronomical facilities in the Northern Hemisphere; its fleet of telescopes includes the 10.4 m Gran Telescopio Canarias , the world's largest single-aperture optical telescope as of July 2009, the William Herschel Telescope (second largest in Europe), and the adaptive optics corrected Swedish 1-m Solar Telescope . The observatory was established in 1985, after 15 years of international work and cooperation by several countries, with
150-695: The observatory goes back to 1969, with the start of the Northern Hemisphere Observatory project. After ten years of research on the site there was a big international agreement between several nations to establish an international Observatory at La Palma. The observatory began operation around 1984 with the Isaac Newton Telescope , which was moved to La Palma from the Royal Greenwich Observatory site at Herstmonceux Castle in East Sussex , England . The move
165-445: The sky above it. 49 of these detectors were spread in a 7-by-7 grid to observe the amplitude and the time of arrival of the front of Cherenkov light. Another 48 were added later on. These counters had a wide field of view but could only be operated during clear, moonless nights, like the atmospheric Cherenkov telescopes. Their energy threshold was a few 10 eV. The AIROBICC array has been dismantled. The first detector type of HEGRA
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#1732783990637180-481: Was officially inaugurated on 29 June 1985 by the Spanish royal family and six European heads of state. Four helicopter pads were built at the observatory to allow the dignitaries to arrive in comfort. The observatory has expanded considerably over time, with the 4.2m William Herschel Telescope opened in 1987, the Nordic Optical Telescope in 1988 and several smaller solar or specialized telescopes;
195-716: Was sensitive to all types of charged secondary particles. To be able to select secondary muons in air showers there were the Muon 'Towers' with 16 m area each. Seventeen of these detectors were installed on La Palma. There were two more types of detectors at the HEGRA site: the CRT (Cosmic Ray Tracking) [1] and the CLUE (Cherenkov Light Ultraviolet Experiment) [2] Archived 2020-05-20 at the Wayback Machine . A remarkable achievement of
210-514: Was the array of 1 m scintillation counters which were used to measure the numbers and arrival times of secondary particles in air showers arriving at ground level. More than 250 of these counters were in operation, spread over a 180-by-180 m area. These detectors were operated day and night at any weather. The energy threshold of the scintillator array was between 40 and 100 TeV, depending on the kind of primary cosmic ray particle. The scintillator array has been dismantled as well. The scintillator array
225-608: Was troubled, and it is widely recognized that it would have been cheaper to build a new telescope on-site rather than to move an existing one. The observatory was first staffed by representatives from Spain , Sweden , Denmark and the United Kingdom . Other countries which became involved later include Germany , Italy , Norway , the Netherlands , Finland , Iceland , and the United States . The observatory
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