An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < abs emi per > >>

Number of Results: 59 Search : miss
absorptivity-emissivity ratio
  وابر ِ درشما‌یی-گسیلا‌یی   
vâbar-e daršamâyi/gosilâyi

Fr.: rapport absorptivité-émissivité   

For a spatial object, the ratio between its absorption of solar radiation and its infrared emission.

absorptivity; → emissivity; → ratio.

alpha emission
  گسیل ِ آلفا   
gosil-e âlfâ

Fr.: émission alpha   

The release of → alpha particles at high velocity from an atom's nucleus as it undergoes radioactive transformation.

alpha; → emission.

atmospheric emission
  گسیل ِ جوی   
gosil-e javvi

Fr.: émission atmosphérique   

The emission of electromagnetic radiation from the atmosphere due to thermal and → non-thermal processes. → Thermal emission comes mainly from → water vapor. Non-thermal processes result in emission lines oxygen (optical) and OH (near-IR). Atmospheric emission is a very significant source of noise in astronomical observations. See also → airglow, → aurora.

atmospheric; → emission.

auroral emission
  گسیل ِ اوشه‌ای   
gosil-e uše-yi

Fr.: émission aurorale   

The → electromagnetic radiation emitted in planetary atmospheres involving the → aurora phenomenon.

auroral; → emission.

ballistic missile
  موشک ِ پرتابیک   
mušak-e partâbik (#)

Fr.: missile balistique   

A missile that after being launched and guided in the early part of its flight, travels unpowered in a ballistic trajectory.

ballistic; → missile.

  راه اندازش   

Fr.: rodage   

Putting a telescope or an observing instrument into active service after their final construction.

From L. commissionem "delegation of business," from commissus, p.p. of committere "to bring together," from → com- "together" + mittere "to put, send."

Râhandâzeš, verbal noun from compound verb râhandâxtan "to set in work; to prepare," from râh "way, path" + andâxtan "to cast; to make, do; to throw."

commissioning period
  دوره‌ی ِ راه اندازش   
dowre-ye râhandâzeš

Fr.: période de rodage   

A period during which a newly constructed observing instrument is used for test.

commissioning; → period.

Comptonized emission
  گسیل ِ کامپتونیده   
gosil-e Kâmptonidé

Fr.: émission comptonisée   

Emission undergone → Comptonization.

Comptonize; → emission.

continuum emission
  گسیل ِ پیوستار   
gosil-e peyvastâr

Fr.: émission continuum   

A continuous radiation produced by three processes: radiative recombination due to transition between electron free-free states, two-photon decays of metastable levels, and thermal bremsstrahlung.

continuum; → emission.

diffuse transmission
  تراگسیل ِ پخشیده   
tarâgosil-e paxšidé

Fr.: transmission diffuse   

Transmission accompanied by diffusion or scatter to the extent that there is no regular or direct transmission.

diffuse; → transmission.

dust emission
  گسیل ِ غبار   
gosil-e qobâr

Fr.: émission des poussières   

Thermal emission in infrared from interstellar → dust grains receiving photons. Dust grains absorb ultraviolet and visible light emitted by nearby stars and re-radiate in the infrared wavelengths. Since the infrared light is of lower energy than the ultraviolet/visible light, the difference goes into heating the dust grain. Typical temperatures for interstellar grains are tens of degrees Kelvin.

dust; → emission.

gosil (#)

Fr.: émission   

In an atom, a characteristic amount of energy radiated (as line emission) when an electron moves from an outer orbit to an inner orbit around the nucleus, corresponding to the lost energy of the electron.

From L. emissionem "a sending out," from emiss-, stem of emittere "send forth," from → ex- "out" + mittere "to send."

Gosil, variant gosi "sending away, dismission;" Mid.Pers. wisé "to despatch" (Parthian Mid.Pers. wsys- "to despatch;" Buddhist Mid.Pers. wsydy "to despatch;" Sogdian 'ns'yd- "to exhort"), from Proto-Iranian *vi-sid- "to despatch, send off," from prefix vi- "apart, away, out," + *sid- "to call."

emission band
  باند ِ گسیلی   
bând-e gosili

Fr.: bande d'émission   

In a spectrum, a combination of several closely spaced, often unresolved, → emission lines occurring across a limited range of wavelengths.

emission; → band.

emission coefficient
  همگر ِ گسیل   
hamgar-e gosil

Fr.: coefficient d'émission   

Electromagnetic flux emitted by a source per unit volume per unit time.

emission; → coefficient.

emission feature
  آرنگ ِ گسیل   
ârang-e gosil

Fr.: motif d'émission   

Any emission mark in the spectrum of a celestial object resulting from line formation or of unknown origin.

emission; → feature.

emission line
  خط ِ گسیلی   
xatt-e gosili (#)

Fr.: raie d'émission   

A bright line in the electromagnetic spectrum of a radiating substance caused by emission at a particular wavelength.

emission; → line.

emission measure
  اندازه‌ی ِ گسیل   
andâze-ye gosil

Fr.: mesure d'émission   

The product of the square of the electron density times the linear size of the emitting region (in parsecs).

emission; → measure.

emission nebula
  میغ ِ گسیلی   
miq-e gosil-i

Fr.: nébuleuse en émission   

An ionized nebula whose spectrum consists of → emission lines. → planetary nebula; → H II region.

emission; → nebula.

emission spectrum
  بیناب ِ گسیلی   
binâb-e gosili (#)

Fr.: spectre d'émission   

A spectrum consisting of emission lines, produced when the light does not undergo absorption between the source and the spectrograph.

emission; → spectrum.

  گسیلی، گسیلشی   
gosili, gosileši

Fr.: émissif   

1) Able to emit (radiation, light, or heat).
2) Pertaining to → emission.

Verbal adj. from → emit.

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