An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < alp mas > >>

Number of Results: 33 Search : emission
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.

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.

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.

forbidden emission line
  خط ِ گسیلی ِ بژکم   
xat-e gosili-ye bažkam

Fr.: raie d'émission interdite   

A → forbidden line in → emission.

forbidden; → emission; → line.

free-bound emission
  گسیل ِ آزاد-بندیده   
gosil-e âzâd-bandidé

Fr.: émission libre-liée   

The radiation emitted when a → free electron is captured by an → ion. See also: → free-free emission; → bound-free transition.

free; → bound; → emission.

free-free emission
  گسیل ِ آزاد-آزاد   
gosil-e âzâd-âzâd (#)

Fr.: emission libre-libre   

Electromagnetic radiation produced in a → plasma by → free electrons scattering off → ions without being captured. The electrons are free before the interaction and remain free afterward.

free; → emission.

induced emission
  گسیل ِ درهاخته، ~ ِ درهازیده   
gosil-e darhâxté, ~ darhâzidé

Fr.: émission induite   

The emission of radiation from an atom when it is bombarded by photons. The induced radiation has the same wavelength and direction as the bombarding radiation. Same as → stimulated emission.

induced; → emission.

infrared emission
  گسیل ِ فروسرخ   
gosil-e forusorx

Fr.: émission infrarouge   

The portion of → electromagnetic radiation from → astrophysical objects in → infrared frequencies.

infrared; → emission.

low-ionization nuclear emission-line region
  ناحیه‌ی ِ هسته‌ای با خط ِ گسیلی ِ کم‌یونش   
nâhiye-ye hasteyi bâ xatt-e gosili-ye kamyoneš (#)

Fr.: Noyau de galaxie à raies d'émission de faible ionisation   

Same as → LINER.

low; → ionization; → nuclear; → emission; → line; → region.

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