An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 742
radio flux density
  چگالی ِ شار ِ رادیویی   
cagâli-ye šârr-e râdioyi

Fr.: densité de flux radio   

The flux of → radio waves that falls on a → detector per → unit → surface area of the detector per unit → bandwidth of the radiation per unit → time. The unit is → jansky.

radio; → flux; → density.

radio frequency
  بسامد ِ رادیویی   
basâmad-e râdio-yi (#)

Fr.: fréquence radio   

The → electromagnetic radiation with the frequency range between 3 → kiloherz (kHz) to 300 → gigahertz (GHz). See also → radio wave.

radio; → frequency.

radio galaxy
  رادیو-کهکشان، کهکشان ِ رادیویی   
râdio kahkešân, kahkešân-e râdioyi

Fr.: radiogalaxie   

A galaxy that is extremely luminous at radio wavelengths between 10 MHz and 100 GHz. The radio luminosity of a strong radio galaxy (1037-1039 watts) can be up to a million times greater than the radio output of an ordinary galaxy and up to a hundred times greater than the optical luminosity of a galaxy such as the Milky Way. The optical counterparts of radio galaxies are usually an → elliptical galaxy. Radio galaxies often exhibit jet structure from a compact nucleus. They typically display two → radio lobes that are often approximately aligned with the jets observed in the optical and that may extend for millions of → light-years.

radio; → galaxy.

radio interferometer
  اندرزنش‌سنج ِ رادیویی   
andarzanešsanj-e râdioyi

Fr.: interféromètre radio   

An → interferometer designed for radio frequencies.

radio; → interferometer.

radio jet
  رادیو-شان، شان ِ رادیویی   
radio-šân, šân-e râdioyi

Fr.: jet radio   

An → astrophysical jet appearing in the radio wavelengths of the electromagnetic spectrum.

radio; → jet.

radio lobe
  لپ ِ رادیویی   
lap-e râdioyi

Fr.: lobe radio   

An extended region of diffuse radio emission, often dumbbell shaped, that surrounds a radio galaxy.

radio; → lobe.

radio noise
  نوفه‌ی ِ رادیویی   
nufe-ye râdioyi (#)

Fr.: bruit radio   

The electromagnetic noise at radio wavelengths.

radio + → noise.

radio pulsar
  رادیو-تپار، پولسار ِ رادیویی   
râdio-tapâr, pulsâr-e râdio-yi

Fr.: pulsar radio   

A → pulsar that emits → pulses in → radio waves. The bulk of discovered pulsars are radio pulsars. There is a small number of pulsars that emit at optical wavelengths, X-ray wavelengths, and gamma-ray wavelengths.

radio; → pulsar.

radio recombination line
  خط ِ بازمیازش ِ رادیویی   
xatt-e bâzmiyâzeš-e râdioyi

Fr.: raie de recombinaison radio   

A → recombination line whose wavelength lies in the radio range of the electromagnetic spectrum. Radio recombination lines are the result of electronic transitions between high energy levels (n > 50) in an atom or ion.

radio; → recombination line.

radio signal
  نشال ِ رادیویی   
nešâl-e râdio-yi

Fr.: signal radio   

A signal in the → radio frequency region of the → electromagnetic spectrum.

radio; → signal.

radio silence
  بیدنگی ِ رادیویی   
bidengi-ye râdioyi

Fr.: silence radio   

A condition in which all fixed or mobile equipments capable of radio transmitting in an area are kept inoperative, typically for the duration of some sensitive time period. The term has both military and civilian applications.

radio; → silence.

radio source
  رادیو-خن، خن ِ رادیویی   
râdio-xan, xan-e râdioyi

Fr.: radio source, source radio   

A point or small portion of the sky giving stronger radio emission than the sky in its vicinity.

radio; → source.

radio spectrum
  بیناب ِ رادیویی   
binâb-e râdio-yi

Fr.: spectre radio   

That part of the → electromagnetic spectrum that includes → radio waves.

radio; → spectrum.

radio star
  رادیو-ستاره، ستاره‌ی ِ رادیویی   
râdio setâré, setâre-ye râdioyi

Fr.: étoile radio   

A star which is a source of emission at radio frequencies. Radio stars include pulsars, flare stars, binary star systems in which mass is transferred from one component to the other, and some X-ray stars.

radio; → star.

radio storm
  توفان ِ رادیویی   
tufân-e radioyi (#)

Fr.: orage radio   

Strong radio frequency radiation from the Sun, occurring in association with eruptions of solar flares or other causes of solar activity.

radio; → storm.

radio Sun
  خورشید ِ رادیویی   
xoršid-e râdioyi (#)

Fr.: Soleil radio   

The image of the Sun obtained from its electromagnetic radiation in radio frequencies. The apparent size of the radio Sun depends of the frequency of the signal, since different radio frequencies originate from various atmospheric layers of the Sun.

radio; → sun.

radio survey
  بردید ِ رادیویی   
bardid-e râdio-yi

Fr.: relevé radio   

A map or series of images of a region of sky obtained in → radio wavelengths of the → electromagnetic radiation.

radio; → survey.

radio telescope
  رادیو-تلسکوپ، تلسکوپ ِ رادیویی   
râdio-teleskop (#), teleskop-e râdioyi (#)

Fr.: radio télescope   

A telescope whose receiver is sensitive to → radio waves.

radio; → telescope.

radio wave
  موج ِ رادیویی   
mowj-e râdioyi (#)

Fr.: ondes radio   

The → electromagnetic radiation with the longest → wavelengths (and lowest energies), ranging from 0.3 mm to several km. Radio waves form a very broad category, which includes the → submillimeter waves (with a wavelength of 0.3-1 mm) and → microwave regions (1 mm to several cm).

radio; → wave.

radio wavelength
  موج-طول ِ رادیویی   
mowjtul-e râdioyi

Fr.: longueur d'onde radio   

The → electromagnetic radiation with a wavelength ranging from 1 mm to several 100 km. See so → radio wave.

radio; → wavelength.

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