An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 26 Search : interstellar
diffuse interstellar band (DIB)
  باند ِ پخشیده‌ی ِ اندر‌اختری   
bând-e paxšide-ye andaraxtari

Fr.: bande diffuse interstellaire   

Absorption features in the spectrum of stars identified in the ultraviolet, visible, and infrared regions. They have an interstellar origin, but despite extensive efforts, their carrier(s) have not yet been clearly identified. See also → Aromatic Infrared Bands; → polycyclic aromatic hydrocarbons.

diffuse; → interstellar; → band.

diffuse interstellar band carrier
  برنده‌ی ِ باند ِ پخشیده‌ی ِ اندر‌اختری   
barande-ye bând-e paxšide-ye andaraxtari

Fr.: porteur des bandes diffuses interstellaires   

The chemical element or composition that is supposedly at the origin of a → diffuse interstellar band (DIB).

diffuse; → interstellar; → band; → carrier.

diffuse interstellar cloud
  ابر ِ اندر‌اختری ِ پخشیده   
abr-e andaraxtari-ye paxšidé

Fr.: nuage interstellaire diffus   

An → interstellar cloud in which hydrogen is completely dissociated and which is less dense and dusty than → molecular clouds. In diffuse interstellar clouds photoabsorption of the background → ultraviolet (UV) radiation field is an important dissociating and ionizing process. Typical densities and temperatures of diffuse clouds are 102 to 103 cm-3 and 20 to 100 K respectively. Because of modest extinctions (≤ 1 mag), → photodissociation processes are important in diffuse clouds preventing the formation of larger molecules.

diffuse; → interstellar; → cloud.

diffuse interstellar medium
  مدیم ِ اندر‌اختری ِ پخشیده   
madim-e andaraxtari-ye paxšidé

Fr.: milieu interstellaire diffus   

The interstellar matter outside condensed molecular clouds. Diffuse interstellar medium consists of a hot intercloud medium, a warm intercloud medium, and a cold neutral medium with hydrogen atom densities nH ~ 0.003, ~ 0.25, and ~ 40 cm-3, and mean gas → kinetic temperatures Tk ~ 5 x 105, ~ 104, and 80 K, respectively.

diffuse; → interstellar; → medium.

interstellar
  اندر-اختری   
andaraxtari

Fr.: interstellaire   

Referring to the medium or objects lying in the space between stars in our Galaxy or outer galaxies.

inter- + → stellar.

interstellar absorption
  درشم ِ اندر-اختری   
daršam-e andaraxtari

Fr.: absorption interstellaire   

The absorption of light from stars and other objects by intervening gas and dust in interstellar space.

interstellar; → absorption.

interstellar bubble
  تنگل ِ اندر-اختری، حباب ِ ~   
tangol-e andaraxtari, hobâb-e ~

Fr.: bulle interstellaire   

A huge structure of ionized gas blown into the interstellar medium by the winds of supernovae and massive stars. → Local Bubble.

interstellar; → bubble.

interstellar cloud
  ابر ِ اندر‌اختری   
abr-e andaraxtari

Fr.: nuage interstellaire   

An aggregation of gas and dust in the → interstellar medium containing large quantities of atoms, molecules, and dust. There are several types of interstellar clouds, such as → diffuse interstellar clouds, → dark clouds, → molecular clouds.

diffuse; → cloud.

interstellar dust
  غبار ِ اندر-اختری   
qobâr-e andaraxtari

Fr.: poussière interstellaire   

An aggregation of → dust grains in the space between stars. Interstellar dust absorbs, scatters, and polarizes the light from distant stars, causing the → interstellar extinction. Large dark regions in the plane of the Milky Way and other galaxies are caused by → intervening clouds of dust. The conclusive proof for the presence of a general and selective interstellar absorption is due to R. J. Trumpler (1930). See also → reddening; → very small grain; → big grain; → PAH.

interstellar; → dust.

interstellar dust grain
  دانه‌ی ِ غبار ِ اندر‌اختری   
dâne-ye qobâr-e andaraxtari

Fr.: grain de poussière interstellaire   

dust grain.

interstellar; → dust; → grain.

interstellar extinction
  خاموشی ِ اندر-اختری   
xâmuši-ye andaraxtari

Fr.: extinction interstellaire   

The dimming of light traveling in the interstellar space due to the combined effects of absorption and scattering by interstellar dust particles. Interstellar extinction increases at shorter (bluer) wavelengths, resulting in → interstellar reddening.

interstellar; → extinction.

interstellar gas
  گاز ِ اندر-اختری   
gâz-e andaraxtari

Fr.: gaz interstellaire   

Gas, mostly hydrogen, in the interstellar space found in a variety of forms: molecular, atomic, ionized, plasma.

interstellar; → gas.

interstellar grain
  دانه‌ی ِ اندر-اختری   
dâne-ye andaraxtari

Fr.: grain interstellaire   

Irregularly shaped → dust grains that occur in the → interstellar medium. They are mostly composed of carbon and/or silicates and measure a fraction of micron across.

interstellar; → grains.

interstellar line
  خطّ ِ اندر-اختری   
xatt-e andaraxtari

Fr.: raie interstellaire   

A spectral line formed in the interstellar medium, in particular an absorption line which does not participate in the periodic Doppler shift of intrinsic absorption lines in a binary star.

interstellar; → line.

interstellar magnetic field
  میدان ِ مغناتیسی ِ اندر-اختری   
meydân-e meqnâtisi-ye andaraxtari

Fr.: champ magnétique interstellaire   

A large-scale, weak magnetic field, with an estimated strength of about 1 to 5 microgauss, that pervades the disk of the Milky Way Galaxy and controls the alignment of interstellar dust grains.

interstellar; → magnetic; → field.

interstellar maser
  میزر ِ اندر-اختری   
meyzer-e andaraxtari

Fr.: maser interstellaire   

A maser phenomenon created by young stars and → protostars in the surrounding dense → molecular clouds of gas and dust. See also → circumstellar maser; → ammonia maser; → methanol maser; → OH maser; → water maser.

interstellar; → maser.

interstellar matter
  مادّه‌ی ِ اندر-اختری   
mâdde-ye andaraxtari

Fr.: matière interstellaire   

The gas and dust that exists in open space between the stars. See also → interstellar medium.

interstellar; → matter.

interstellar medium (ISM)
  مدیم ِ اندر-اختری   
madim-e andaraxtari

Fr.: milieu interstellaire   

The environment containing the → interstellar matter, consisting of gas (mostly hydrogen) and dust. Even at its densest phase, the interstellar medium is emptier than the best vacuum man can create in the laboratory, but because space is so vast, the interstellar medium still adds up to a huge amount of mass.

interstellar; → medium.

interstellar molecule
  مولکول ِ اندر-اختری   
molekul-e andaraxtari

Fr.: molécule interstellaire   

Any molecule that occurs naturally in clouds of gas and dust in the interstellar medium. So far more than 140 species have been discovered, many of which nonexistent on Earth.

interstellar; → molecule.

interstellar polarization
  قطبش ِ اندر-اختری   
qotbeš-e andaraxtari

Fr.: polarisation interstellaire   

The polarization of starlight caused by aligned → interstellar grains, so that initially → unpolarized light from a star is partially polarized by the time it reaches the Earth.

interstellar; → polarization.

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