Radio astronomy is a section of astronomy that studies space objects by studying their electromagnetic radiation in the range of radio waves . Objects of radiation are practically all space bodies and their complexes (from the bodies of the Solar system to the Metagalaxy ), as well as matter and fields that fill space ( interplanetary medium , interstellar gas , interstellar dust and magnetic fields , cosmic rays , relic radiation , etc. .). Research method - registration of cosmic radio emission using radio telescopes . [one]
Content
History of radio astronomy
At the end of the 19th century, scientists assumed that radio waves , which differ from visible light only by frequency , should also be emitted by celestial bodies , in particular, by the Sun [2] . Radio astronomy as a science originates from the experiments of Karl Jansky , conducted in 1931 [3] . In December 1932, Jansky announced the discovery of radio emission of cosmic origin, which was reliably established over the next few years [4] [5] . The first to be found was the strongest continuous-wave radio source, in the center of the Milky Way [6] . In 1937, Grout Reber , inspired by the discovery of Jansky , built the first parabolic radio telescope with a diameter of 9.5 m [3] . The first radio maps of the firmament were obtained by Reber , and published in 1944 in [7] . The maps clearly show the central regions of the Milky Way and bright radio sources in the constellation Sagittarius , Cygnus A , Cassiopeia A , Canis Major and Korma . After World War II , significant technological improvements were made by scientists in Europe , Australia and the USA , which contributed to the rapid development of modern radio astronomy.
Exact copy of the Karl Jansky radio telescope
The first recording of the Milky Way radio emission
An exact copy of the Grote Reber radio telescope
The first sky radio map
Tools
Radio telescopes
The radio telescope is an astronomical tool for receiving its own radio emission from celestial objects (in the Solar System , Galaxy and Metagalaxy ) and studying their characteristics, such as: coordinates , spatial structure, radiation intensity, spectrum and polarization [8] .
The radio telescope occupies the initial, over the frequency range , position among astronomical instruments investigating electromagnetic radiation - the telescopes of thermal , visible , ultraviolet , X-ray and gamma radiation are more high-frequency [9] .
Radio Interferometers
A radio interferometer is a tool for radio astronomy observations with a high angular resolution , which consists of at least two antennas spaced apart and connected by a cable link [10] [11] . Radio interferometers are used to measure thin corner parts in the sky radio emission [12] . In particular, with their help, very precise coordinates and angular sizes of astronomical objects are obtained, as well as radio images of celestial bodies with high resolution [13] .
Superlong radio interferometers
Radio interferometry with super-long bases (VLBI, very long Baseline Interferometry, VLBI ) is a type of interferometry used in radio astronomy, in which the receiving elements of the interferometer ( telescopes ) are located no closer than at continental distances from each other. In this case, the control of the elements of the VLBI interferometer is carried out independently, without a direct switching link, in contrast to a conventional radio interferometer . Data recording is carried out on information carriers with subsequent correlation processing on specialized computing equipment - the correlator . [14]
Astronomical sources
Radio astronomy led to a significant development of astronomy , especially with the discovery of several new classes of objects, including pulsars , quasars and radio galaxies . All this is due to the fact that radio astronomy allows you to see what is impossible to detect using optical astronomy . Such objects are the most distant and powerful physical phenomena in the universe.
Relic radiation was also first detected using radio telescopes . In addition, radio telescopes were used to study astronomical objects closest to the Earth , including observations of the Sun and solar activity , and radar mapping of the planets of the solar system .
See also
- Radar astronomy
Notes
- ↑ Smoker, 1986 , p. 533.
- ↑ Kaplan S. А. How did radio astronomy originate // Elementary radio astronomy. - M .: Science, 1966. - p. 12. - 276 p. (Checked September 28, 2011)
- ↑ 1 2 Kraus J. D. 1.2. Brief history of the first years of radio astronomy // Radio astronomy / Ed. V. V. Zheleznyakov. - M .: Soviet radio, 1973. - pp. 14-21. - 456 s. Archived copy from March 1, 2012 on Wayback Machine (Tested 12 August 2011)
- ↑ Jansky KG Directional Studies of Atmospherics at Hight Frequencies. - Proc. IRE, 1932. - T. 20 . - pp . 1920-1932 . (Checked August 12, 2011)
- ↑ Jansky KG Electrical disturbances out of extraterrestrial origin (Eng.) = Electrical interference, probably of extraterrestrial origin. - Proc. IRE, 1933. - Vol. 21 . - P. 1387-1398 . (Checked August 12, 2011)
- ↑ Jansky KG A note on the source of interstellar interference .. - Proc. IRE, 1935. - T. 23 . - p . 1158-1163 . (Checked August 12, 2011)
- ↑ Reber G. Cosmic Static. - Astrophys. J., November, 1944. - T. 100 . - p . 279-287 . (Checked September 7, 2011)
- ↑ Radio telescope // Great Soviet Encyclopedia : [in 30 tons] / ch. ed. A. M. Prokhorov . - 3rd ed. - M .: Soviet Encyclopedia, 1969-1978.
- ↑ Electromagnetic Radiation
- ↑ Radio interferometer . Great Soviet Encyclopedia . 3rd edition (1978). The appeal date is February 26, 2012. Archived April 6, 2012. (Checked November 16, 2011)
- ↑ Radiointerferometer / Matveenko L.I. // Space Physics: A Little Encyclopedia / Redcol .: R. A. Sunyaev (Gl. Ed.) And others - 2nd ed. - M .: Soviet Encyclopedia , 1986. - p. 547-551. - 783 s. - 70 000 copies (Checked November 16, 2011)
- ↑ Thompson et al., 2003 , p. eleven.
- ↑ Konnikova V. K., Lekht E. E., Silantyev N. A. 6.4. Interferometers // Practical radio astronomy / M. G. Mingaliev, M. G. Larionov. - Moscow : Moscow State University, 2011. - p. 241. - 304 p. (Checked November 29, 2011)
- ↑ Thompson et al., 2003 , p. 276.
Literature
- Radio astronomy / Kurilchik VN // Physics of the cosmos: The Little Encyclopedia / Redkol .: R. A. Syunyaev (Gl. Ed.) And others. - 2nd ed. - M .: Soviet Encyclopedia , 1986. - p. 533-541. - 783 s. - 70 000 copies
- Thompson A. R. , Moran D. M. , Swenson D. U. Interferometry and synthesis in radio astronomy = Interferometry and synthesis in radio astronomy / Trans. from English by ed. L.I. Matveyenko . - 2nd ed. - M .: FIZMATLIT, 2003. - 624 p. - ISBN 5-9221-0015-7 .
Links
- G. M. Rudnitsky, Lecture notes for the course “Radio Astronomy”
- A. Levin. Listening to the Universe // Popular Mechanics . - 2009. - Vol. 8
- Sounds of the cosmos