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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 12 Search : redshift
anomalous redshift
  سرخ-کیب ِ ناسان   
sorx-kib-e nâsân

Fr.: décalage anormal vers le rouge   

The high redshift of a quasar which is seemingly physically associated with a galaxy of low redshift.

anomalous; → redshift.

cosmological redshift
  سرخ کیب ِ کیهان‌شناسیک، ~ کیهان‌شناختی   
sorxkib-e keyhânšenâsik, ~ keyhânšenâxti

Fr.: décalage vers le rouge cosmologique, redshift ~   

The → redshift of a remote object (galaxy, quasar, supenova) due to the expansion of the Universe.

cosmological; → redshift.

gravitational redshift
  سرخ‌کیب ِ گرانشی   
sorxkib-e gerâneši

Fr.: décalage vers le rouge gravitationnel   

The change in the wavelength or frequency of electromagnetic radiation in a gravitational field predicted by general relativity.

gravitational; → redshift.

high redshift object
  بر‌آخت ِ مه-سرخ‌کیب   
barâxt-e meh-sorxkib

Fr.: objet à grand décalage vers le rouge   

A galaxy or quasar having a → redshift larger than about 0.8, corresponding to a → look-back time half the present age of the Universe. The qualifier "high" is, however, relative and depends on context and authors' assessment.

high; → redshift; → object.

low redshift
  که‌سرخ‌کیب   
keh sorxkib

Fr.: faible décalage vers le rouge   

A redshift characterizing a near-by receding object.

low; → redshift.

redshift
  سرخ‌کیب   
sorxkib

Fr.: décalage vers le rouge   

A shift in the lines of an object's spectrum toward longer wavelengths. Redshift indicates that an object is moving away from the observer. The larger the redshift, the faster the object is moving. Redshift is expressed by z = Δλ/λ = v/c, where λ is the wavelength, Δλ the wavelength shift, v the velocity of the source relative to the observer, and c the → speed of light. When v approaches c, redshift is expressed by the → relativistic formula z = ((1 +v/c)/(1 - v/c))½ - 1.

red; → shift.

redshift space
  فضای ِ سرخ-کیب   
fazâ-ye sorx-kib

Fr.: espace de décalage vers le rouge   

The space corresponding to → redshift measurements, as contrasted with real space. See also → redshift space distortion

redshift; → space.

redshift space distortion
  چولگی ِ فضای ِ سرخ-کیب   
cowlegi-ye fazâ-ye sorx-kib

Fr.: distorsion dûe aux vitesses particulières sur la ligne de visée   

The distortion observed in → redshift space of → galaxy clusters caused by peculiar velocities of the members (→ peculiar velocity). In a perfectly homogeneous → Friedmann-Lemaitre Universe the redshifts would accurately measure radial distances from the observer, and the mapping from real space to redshift space would simply be an identity. In an inhomogeneous Universe the peculiar velocities associated with any inhomogeneous structure will introduce a distortion in this mapping (N. Kaiser, 1987, MNRAS 227, 1). See also: → fingers of God, → Kaiser effect.

redshift; → space; → distortion;.

redshift survey
  بردید ِ سرخ‌کیب   
bardid-e sorx kib

Fr.: relevé de décalages vers le rouge   

A survey of a large region of the sky to measure the redshifts of all the galaxies down to a certain limiting magnitude.

redshift; → survey.

redshift-distance relation
  بازانش ِ سرخ‌کیب-دورا   
bâzâneš-e sorxkib-durâ

Fr.: relation décalage vers le rouge-distance   

The correlation, first established by E. Hubble, between the cosmological recession velocities of galaxies and their distances.

redshift; → distance; → relation.

redshifted line
  خط ِ سرخ‌کیبیده   
xatt-e sorx kibideh

Fr.: raie décalée vers le rouge   

A spectral line whose wavelength does not coincide with its theoretical value and is shifted toward longer wavelengths.

red; → shift; → line.

relativistic redshift
  سرخ‌کیب ِ بازانیگی‌مند   
sorx kib-e bâzânigimand

Fr.: décalage vers le rouge relativiste   

A redshift caused by the → relativistic Doppler effect. → gravitational redshift.

relativistic; → redshift.