An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 12 Search : clump
clump
  گوده   
gudé

Fr.: grumeau   

1) A compact mass, in particular that contained in a less dense environment.
2) → molecular clump.

Clump, from Du. klomp "lump, mass," or Low Ger. klump.

Gudé "ball, bowl, tumour" in Gilaki, cf. Skt. guda- "ball, mouthful, lump, tumour," Gk. gloutos "rump," L. glomus "ball," globus "globe," Ger. Kugel, E. clot, PIE *gel- "to make into a ball."

clumped wind
  باد ِ گوده‌دار   
bâd-e gudedâr

Fr.: vent grumelé   

A → radiation-driven wind of → Wolf-Rayet and → O stars, which is not homogeneous, and contains compressions and rarefactions in the form of density clumps. Observationally, wind clumping appears as moving, small-scale structures in spectral line profiles. Indirect indicators of wind clumping include: electron scattering wings of emission lines, too-weak observed UV line profiles, and shapes of X-ray lines. The most likely physical explanation for the presence of these clumps is an instability in radiatively-driven winds. The inclusion of a clumping factor in the models of W-R winds reduces the → mass loss rates by a factor ~ 2-4 relative to homogeneous models. See also → clumping factor.

clumpy; → wind.

clumpiness
  گودگی   
gudegi

Fr.: grumelosité   

Of a → molecular cloud, the property of being made up of → clumps.
The extent with which a molecular cloud is → clumpy.

Clumpiness, from → clumpy + → -ness.

Gudegi from gudé, → clump, + -gi suffix forming noun from adjectives ending in .

clumping
  گوده‌داری   
gudedâri

Fr.: grumelage   

The massing together of material to form clumps. → wind clumping.

clump; → -ing.

clumping factor
  کروند ِ گوده‌داری   
karvand-e gudedâri

Fr.: facteur de grumelage   

The ratio fcl = <ρ2> / <ρ >2, where ρ represents the → stellar wind density and the brackets mean values. Unclumped wind has fcl = 1 and → clumping becomes significant for fcl≅ 4.

clumping; → factor.

clumpy
  گوده‌دار   
gudedâr

Fr.: grumeleux   

Of a → molecular cloud, being composed of → clumps.

Clumpy, from → clump + -y suffix meaning "full of or characterized by," from O.E. -ig, from P.Gmc. *-iga, akin to Gk. -ikos, L. -icus, → -ics.

Gudedâr, from gudé, → clump, + dâr "having, possessor," from dâštan "to have, to possess," O.Pers./Av. root dar- "to hold, keep back, maitain, keep in mind," Skt. dhr-, dharma- "law," Gk. thronos "elevated seat, throne," L. firmus "firm, stable," Lith. daryti "to make," PIE *dher- "to hold, support."

clumpy galaxy
  کهکشان ِ گوده‌دار   
kahkešân-e gudedâr

Fr.: galaxie grumeleuse   

An irregularly shaped, clumpy → star-forming galaxy that does not fall anywhere on the → Hubble sequence and appears frequently at → redshifts z ~ 1-4. Galaxies at z ≤ 1 with similar morphologies and enhanced → star formation have been identified, but become less common with decreasing redshift. Clumpy galaxies are prominent in the → early Universe.

clumpy; → galaxy.

interclump medium
  مدیم ِ اندرگوده‌ای   
madim-e andargude-yi

Fr.: milieu inter-grumeau   

The diffuse medium between → clumps inside → molecular clouds.

inter- + → clump + → medium.

molecular clump
  گوده‌ی ِ مولکولی   
gude-ye molekuli

Fr.: grumeau moléculaire   

One of many compact and dense sub-structures in a → molecular cloud. Their typical sizes are about 0.5-10 → parsecs and their masses range from about 50 to 103 → solar masses. The gas temperatures are about 10-20 K, and the number densities from about 103 to 104 cm-3.

molecular; → clump.

red clump
  گوده‌ی ِ سرخ   
gude-ye sorx

Fr.: grumeau rouge   

A concentration, on the → horizontal branch, of → red giant stars that roughly have the same intrinsic brightness. These core → helium burning stars are the metal rich equivalents of the better known → horizontal branch stars. Theoretical models predict that their absolute luminosity only weakly depends on their age and chemical composition.

red; → clump.

red clump star
  ستاره‌ی ِ گوده‌ی ِ سرخ   
setâre-ye gude-ye sorx

Fr.: étoile du grumeau rouge   

A star on the → horizontal branch which results from the evolution of a → red giant with an initial mass of ~ 1 Msun.

red; → clump; → star.

wind clumping
  گوده‌داری ِ باد   
gudedâri-ye bâd

Fr.: grumelage de vent   

The inhomogeneous property of a → radiation-driven wind, or the physical mechanism accounting for the → clumped wind.

clumpy; → wind.