MAGIC (telescope)
Alternative names | MAGIC |
---|---|
Part of | Roque de los Muchachos Observatory |
Location(s) | La Palma, Atlantic Ocean, international waters |
Coordinates | 28°45′43″N 17°53′24″W / 28.761944444444°N 17.89°W |
Altitude | 2,200 m (7,200 ft) |
Wavelength | Gamma rays (indirectly) |
Built | 2004 |
First light | 2004, 2009 |
Telescope style | IACT reflecting telescope gamma-ray telescope |
Diameter | 17 m (55 ft 9 in) |
Collecting area | 236 m2 (2,540 sq ft) |
Focal length | f/D 1.03 |
Mounting | metal structure |
Replaced | HEGRA |
Website | magic |
Related media on Commons | |
MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescopes, later renamed to MAGIC
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.[1]
MAGIC is sensitive to cosmic
Aims
The goals of the telescope are to detect and study primarily photons coming from:
- Accretion of active galactic nuclei
- cosmic rays.
- Other galactic sources such as
- Unidentified EGRET or Fermisources
- Gamma ray bursts
- Annihilation of dark matter
Observations
MAGIC has found pulsed gamma-rays at energies higher than 25 GeV coming from the Crab Pulsar.[4] The presence of such high energies indicates that the gamma-ray source is far out in the pulsar's magnetosphere, in contradiction with many models.
In 2006 MAGIC detected[5] very high energy cosmic rays from the quasar 3C 279, which is 5 billion light years from Earth. This doubles the previous record distance from which very high energy cosmic rays have been detected. The signal indicated that the universe is more transparent than previously thought based on data from optical and infrared telescopes.
MAGIC did not observe cosmic rays resulting from dark matter decays in the dwarf galaxy Draco.[6] This strengthens the known constraints on dark matter models.
A much more controversial observation is an energy dependence in the speed of light of cosmic rays coming from a short burst of the blazar Markarian 501 on July 9, 2005. Photons with energies between 1.2 and 10 TeV arrived 4 minutes after those in a band between 0.25 and 0.6 TeV. The average delay was 30 ±12 ms per GeV of energy of the photon. If the relation between the space velocity of a photon and its energy is linear, then this translates into the fractional difference in the speed of light being equal to minus the photon's energy divided by 2×1017 GeV. The researchers have suggested that the delay could be explained by the presence of quantum foam, the irregular structure of which might slow down photons by minuscule amounts only detectable at cosmic distances such as in the case of the blazar.[7][8]
Technical specifications
Each telescope has the following specifications:
- A collecting area 236 m2 consisting of 956 50 cm × 50 cm aluminium individual reflectors
- A lightweight carbon fibreframe
- A detector consisting of 396 separate hexagonal photomultiplier detectors in the center (diameter: 2.54 cm) surrounded by 180 larger photomultiplier detectors (diameter: 3.81 cm).
- Data are transferred in analogue form by fibre opticcables
- Signal digitization is done via an ADC (analog-to-digital converter) with a 2 GHz sampling rate
- Total weight of 40,000 kg
- Reaction time to move to any position of the sky less than 22 seconds[9]
Each mirror of the reflector is a sandwich of an aluminum
Directing the telescope to different elevation angles causes the reflector to deviate from its ideal shape due to the gravity. To counteract this deformation, the telescope is equipped with Active Mirror Control system. Four mirrors are mounted on each panel, which is equipped with actuators that can adjust its orientation in the frame.
The signal from the detector is transmitted over 162 m optical fibers. The signal is digitized and stored in 32 kB ring buffer. The readout of the ring buffer results in a dead time 20 µs, which corresponds to about 2% dead time at the design trigger rate of 1 kHz. The readout is controlled by an
Collaborating institutions
Physicists from over twenty institutions in Germany, Spain, Italy, Switzerland, Croatia, Finland, Poland, India, Bulgaria and Armenia collaborate in using MAGIC; the largest groups are at
- Institut de Física d'Altes Energies (IFAE), Spain
- Universitat Autònoma de Barcelona, Spain
- Universidad Complutense de Madrid, Spain
- Centro de Investigaciones Energéticas, MedioAmbientales y Tecnológicas (CIEMAT), Spain
- Instituto de Astrofísica de Andalucía, Spain
- Instituto de Astrofísica de Canarias, Spain
- ETHZ, Zürich, Switzerland
- UNIGE, Geneva, Switzerland
- Dipartimento di Fisica and INFN, University of Padua, Italy
- Tuorla Observatory, Piikkiö, Finland
- Dipartimento di Fisica and INFN, University of Siena, Italy
- Dipartimento di Fisica and INFN, University of Udine, Italy
- TU Dortmund University, Germany
- University of Würzburg, Germany
- Max Planck Institute for Physics, Germany
- Institute for Particle Physics, Zürich, Switzerland
- National Institute for Astrophysics (INAF), Italy
- Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
- Croatian MAGIC Consortium (
See also
References
- ^ "Technical status of the MAGIC telescopes", MAGIC collaboration, Proc. International Cosmic Rays Conference 2009, arXiv:0907.1211
- S2CID 20981239.
- S2CID 15302221.
- S2CID 5387958.
- S2CID 16886668.)
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: CS1 maint: date and year (link - S2CID 15324383.
- S2CID 5103618.
- ^ Lee, Chris (2007-08-23). "Probing quantum gravity with gamma ray bursters". Ars Technica. Retrieved 2022-08-10.
- ^ S2CID 16311614.