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IACT
IACT (imaging atmospheric r airCherenkov telescope r technique is a device or method to detect very-high-energy gamma ray photons in the photon energy range of 50 GeV to 50 TeV. As of 2017, there are four operating IACT systems: High Energy Stereoscopic System (H.E.S.S.), Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC), First G-APD Cherenkov Telescope (FACT), and Very Energetic Radiation Imaging Telescope Array System (VERITAS). The Major Atmospheric Cerenkov Experiment Telescope (MACE) is under construction in Hanle, Ladakh, India and is set to be the highest and second-largest IACT. The Cherenkov Telescope Array (CTA) is a multinational project to build next-generation IACTs and is scheduled to begin data collection in 2022. Background Due to the rapidly falling flux of gamma-ray photons from cosmic sources in this energy regime, space-based detectors become ineffective due to their small collection areas which are often limited to some tens o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Energy Stereoscopic System
High Energy Stereoscopic System (H.E.S.S.) is a system of imaging atmospheric Cherenkov telescopes (IACTs) for the investigation of cosmic gamma rays in the photon energy range of 0.03 to 100 TeV. The acronym was chosen in honour of Victor Hess, who was the first to observe cosmic rays. The name also emphasizes two main features of the installation, namely the simultaneous observation of air showers with several telescopes, under different viewing angles, and the combination of telescopes to a large system to increase the effective detection area for gamma rays. H.E.S.S. permits the exploration of gamma-ray sources with intensities at a level of a few thousandth parts of the flux of the Crab Nebula. H.E.S.S. consists of five telescopes: four with mirrors just under 12 m in diameter, arranged as a square with 120 m sides, and one larger telescope with a 28 m mirror, located at the centre of the array. The four 12 m telescopes began operation in 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fred Lawrence Whipple Observatory
The Fred Lawrence Whipple Observatory is an American astronomical observatory owned and operated by the Smithsonian Astrophysical Observatory (SAO); it is their largest field installation outside of their main site in Cambridge, Massachusetts. It is located near Amado, Arizona on the summit of Mount Hopkins. Research activities include imaging and spectroscopy of extragalactic, stellar, solar system and extra-solar bodies, as well as gamma-ray and cosmic-ray astronomy. History In 1966, roadwork began at the site with funding granted for the Smithsonian Mt. Hopkins Observatory. The Whipple 10-meter gamma-ray telescope was constructed in 1968. Formerly known as the Mount Hopkins Observatory, the observatory was renamed in late 1981 in honor of Fred Lawrence Whipple, a planetary expert, space science pioneer, and director emeritus of SAO, under whose leadership the Arizona facility was established. Equipment Whipple observatory hosts the MMT Observatory, which is joint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Ray
Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk are deflected off into space by the magnetosphere or the heliosphere. Cosmic rays were discovered by Victor Hess in 1912 in balloon experiments, for which he was awarded the 1936 Nobel Prize in Physics. Direct measurement of cosmic rays, especially at lower energies, has been possible since the launch of the first satellites in the late 1950s. Particle detectors similar to those used in nuclear and high-energy physics are used on satellites and space probes for research into cosmic rays. Data from the Fermi Space Telescope (2013) have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Major Atmospheric Cerenkov Experiment Telescope
Major Atmospheric Cerenkov Experiment Telescope (MACE) is an imaging atmospheric Cerenkov telescope (IACT) located near Hanle, Ladakh, India. It is the highest (in altitude) and second largest Cerenkov telescope in the world. It was built by Electronics Corporation of India, Hyderabad, for the Bhabha Atomic Research Centre and was assembled at the campus of Indian Astronomical Observatory at Hanle. It was originally scheduled to become operational by 2016, but plans were pushed back to begin operations in 2020. Due to the remote location and harsh environment of the site, the telescope is remotely operated. A dedicated 240 kW solar power station was built to fulfil the power requirements of the observatory. The telescope is the second-largest gamma ray telescope in the world and will help the scientific community enhance its understanding in the fields of astrophysics, fundamental physics, and particle acceleration mechanisms. The largest telescope of the same class is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherenkov Effect
Cherenkov radiation () is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium (such as distilled water) at a speed greater than the phase velocity (speed of Wave propagation, propagation of a wavefront in a medium) of speed of light, light in that medium. A classic example of Cherenkov radiation is the characteristic blue glow of an underwater nuclear reactor. Its cause is similar to the cause of a sonic boom, the sharp sound heard when faster-than-sound movement occurs. The phenomenon is named after Soviet physicist Pavel Cherenkov. History The radiation is named after the Soviet Union, Soviet scientist Pavel Cherenkov, the 1958 Nobel Prize in Physics, Nobel Prize winner, who was the first to detect it experimentally under the supervision of Sergey Vavilov at the Lebedev Physical Institute, Lebedev Institute in 1934. Therefore, it is also known as Vavilov–Cherenkov radiation. Cherenkov saw a faint bluish light ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherenkov Radiation
Cherenkov radiation () is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium (such as distilled water) at a speed greater than the phase velocity (speed of propagation of a wavefront in a medium) of light in that medium. A classic example of Cherenkov radiation is the characteristic blue glow of an underwater nuclear reactor. Its cause is similar to the cause of a sonic boom, the sharp sound heard when faster-than-sound movement occurs. The phenomenon is named after Soviet physicist Pavel Cherenkov. History The radiation is named after the Soviet scientist Pavel Cherenkov, the 1958 Nobel Prize winner, who was the first to detect it experimentally under the supervision of Sergey Vavilov at the Lebedev Institute in 1934. Therefore, it is also known as Vavilov–Cherenkov radiation. Cherenkov saw a faint bluish light around a radioactive preparation in water during experiments. His doctorate thesis was on lumin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very-high-energy Gamma Ray
A very-high-energy gamma ray (VHEGR) is Gamma ray, gamma radiation with photon energy, photon energies of 100 GeV (gigaelectronvolt) to 100 TeV (teraelectronvolt), i.e., 1011 to 1014 electronvolts. This is approximately equal to wavelengths between 10−17 and 10−20 meters, or frequencies of 2 × 1025 to 2 × 1028 Hz. Such energy levels have been detected from emissions from astronomical sources such as some binary star systems containing a compact object. For example, radiation emitted from Cygnus X-3 has been measured at ranges from GeV to Exa-, exaelectronvolt-levels. Other astronomical sources include BL Lacertae, 3C 66A Markarian 421 and Markarian 501. Various other sources exist that are not associated with known bodies. For example, the High Energy Stereoscopic System, H.E.S.S. catalog contained 64 sources in November 2011. Detection Instruments to detect this radiation commonly measure the Cherenkov radiation produced by secondary particles generated from an energetic p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAGIC (telescope)
MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescopes, later renamed to MAGIC Florian Goebel Telescopes) is a system of two Imaging Atmospheric Cherenkov telescopes situated at the Roque de los Muchachos Observatory on La Palma, one of the Canary Islands, at about 2200 m above sea level. MAGIC detects particle showers released by gamma rays, using the Cherenkov radiation, i.e., faint light radiated by the charged particles in the showers. With a diameter of 17 meters for the reflecting surface, it was the largest in the world before the construction of H.E.S.S. II. The first telescope was built in 2004 and operated for five years in standalone mode. A second MAGIC telescope (MAGIC-II), at a distance of 85 m from the first one, started taking data in July 2009. Together they integrate the MAGIC telescope stereoscopic system. MAGIC is sensitive to cosmic gamma rays with photon energies between 50 GeV (later lowered to 25 GeV) and 30 TeV due to its large m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherenkov Telescope Array
The Cherenkov Telescope Array Observatory (CTAO) is a multinational project to build a new generation of ground-based gamma-ray instruments in the energy range extending from some tens of GeV to about 300 TeV. It is proposed as an open observatory and will consist of two arrays of imaging atmospheric Cherenkov telescopes, a first array at the Northern Hemisphere, on the Spanish island of La Palma, with emphasis on the study of extragalactic objects at the lowest possible energies, and a second array at the Southern Hemisphere, in the Atacama Desert in Chile, which is to cover the full energy range and concentrate on galactic sources. The physics program of the CTAO goes beyond high-energy astrophysics into cosmology and fundamental physics. Building on the technology of current-generation ground-based gamma-ray detectors ( MAGIC, HESS, and VERITAS), the CTAO will be ten times more sensitive and have unprecedented accuracy in its detection of high-energy gamma rays. Curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The MAGIC Telescope At Night
''The'' is a grammatical Article (grammar), article in English language, English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the Most common words in English, most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muon
A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of ''ħ'', but with a much greater mass. It is classified as a lepton. As with other leptons, the muon is not thought to be composed of any simpler particles. The muon is an unstable subatomic particle with a mean lifetime of , much longer than many other subatomic particles. As with the decay of the free neutron (with a lifetime around 15 minutes), muon decay is slow (by subatomic standards) because the decay is mediated only by the weak interaction (rather than the more powerful strong interaction or electromagnetic interaction), and because the mass difference between the muon and the set of its decay products is small, providing few kinetic degrees of freedom for decay. Muon decay almost always produces at least three particles, which must include an electron of the same charge as the muon and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab Nebula
The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus (constellation), Taurus. The common name comes from a drawing that somewhat resembled a crab with arms produced by William Parsons, 3rd Earl of Rosse, in 1842 or 1843 using a telescope. The nebula was discovered by English astronomer John Bevis in 1731. It corresponds with SN 1054, a bright supernova observed in 1054 C.E. by Native American, Japanese, and Arabic stargazers; this supernova was also recorded by Chinese astronomy, Chinese astronomers as a Guest star (astronomy), guest star. The nebula was the first astronomical object identified that corresponds with a historically-observed supernova explosion. At an apparent magnitude of 8.4, comparable to that of Titan (moon), Saturn's moon Titan, it is not visible to the naked eye but can be made out using binoculars under favourable conditions. The nebula lies in the Perseus Arm of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
