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: 620
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.

interstellar radiation field
  میدان ِ تابش ِ اندر-اختری   
meydân-e tâbeš andaraxtari

Fr.: champ de rayonnement interstellaire   

A global ionizing radiation in the → interstellar medium provided by various sources all together.

interstellar; → radiation; → field.

interstellar reddening
  سُرخش ِ اندر-اختری   
sorxeš-e andaraxtari

Fr.: rougissement interstellaire   

The dimming of light during its travel in the → interstellar medium due to absorption by → intervening → dust grains. Since shorter wavelengths are particularly affected, the spectrum of the light is increasingly dominated by the long wavelength end of the spectrum. As a result, the light is "reddened" as it travels through space. Robert J. Trumpler (1886-1956), a Swiss-American astronomer, was the first to produce a definite evidence of the existence of → interstellar extinction and to estimate its magnitude (1930).

interstellar; → reddening.

interstellar reddening curve
  خم ِ سُرخش ِ اندر-اختری   
xam-e sorxeš-e andaraxtari

Fr.: courbe de rougissement interstellaire   

A graph showing the relation between → interstellar absorption (in magnitudes) and wavelength.

interstellar; → reddening; → curve.

interstellar scintillation
  سوسوی ِ اندر-اختری   
susu-ye andaraxtari

Fr.: scintillation interstellaire   

An apparent twinkling of the signals from distant point-like radio sources (pulsars). It is due to turbulence, i.e. fluctuations in the electron density of the interstellar ionized gas, through which the signals have passed on their way to Earth.

interstellar; → scintillation.

interstice
  اندرجا   
andarjâ (#)

Fr.: interstice   

1) A minute gap between the adjacent parts of a body or objects close together.
2) In a crystal lattice, the empty space between adjacent atoms. The interstices are of two types: Tetrahedral-interstices and Octahedral-interstices. Also called → interstitial site.

From L. interstitium "space between; interval," from intersistere, from → inter- "between," + stem of stare "to stand," cognate with Pers. istâdan, → stand

Andarjâ, literally "a place between," from andar "between," → inter-, + , → place.

interstitial
  اندرجایی   
andarjâyi

Fr.: interstitiel   

1) Pertaining to, situated in, or forming → interstices.
2) → interstitial atom.

interstice; → -al.

interstitial atom
  اتم ِ اندرجایی   
atom-e andarjâyi

Fr.: atom interstitiel   

In a → crystal, an imperfection caused by the presence of an extra atom that occupies a place outside the normal → lattice position. It may be the same type of atom as the others (self interstitial) or an → impurity atom.

interstitial; → atom.

interstitium
  اندرجایان   
andarjâyân

Fr.: interstitium   

A network of fluid-filled spaces in the body's connective tissues all over the body. It lies below the skin's surface and surrounds arteries, muscles, and the digestive and urinary tracts in a layer long thought to be dense connective tissue. Interstitium could be the largest organ in the human body

From L. interstitium, → interstice.

Andarjâyân, from andarjâ, → interstice, + euphonic sound -y-, + relation suffix -ân.

intersystem
  اندر-راژمان   
andar-râžmân

Fr.: inter-système   

Describing something that involves mutual relations between systems.

inter-; → system.

intersystem crossing
  گذر ِ اندر-راژمانی   
gozar-e andar-râžmâni

Fr.: conversion intersystème   

A → radiationless relaxation process in which a molecule in some excited → electronic state converts to a state of different spin → multiplicity. Intersystem crossing is analogous to → internal conversion.

intersystem; → crossing.

intersystem line
  خط ِ اندر-راژمانی   
xatt-e andar-râžmâni

Fr.: raie semi-interdite   

In spectroscopy, same as → semi-forbidden line.

inter-; → system.

interval
  اندروار   
andarvâr (#)

Fr.: intervalle   

1) Math.: A portion of a real line (i.e. a line with a fixed scale so that every real number corresponds to a unique point on the line) between two designated endpoints. → span.
2) Music: Difference in pitch between two tones of a scale.

From O.Fr. intervalle, from L.L. intervallum, originally "space between two palisades or ramparts," from → inter- "between" + vallum "rampart."

Andarvâr, literally "between walls," from andar-inter- + vâr "wall," as in divâr "wall" (originally "fortress wall," from *dida-vāra-), variant bâru "wall, rampart, fortification; fort; tower;" Mid.Pers. bâr, var "enclosure, defences, fortress;" Av. var- "castle."

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