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: 48 Search : galactic
perigalactic
  پیراکهکشانی   
pirâkahkešâni

Fr.: périgalactique   

Of or pertaining to a → perigalacticon.

peri-; → galactic.

perigalacticon
  پیراکهکشان   
pirâkahkešân

Fr.: périgalacticon   

The point in an object's orbit around a galaxy when the object lies closest to the galactic center; opposite of → apogalacticon.

peri- + → galaxy.

supergalactic
  ابرکهکشانی   
abarkahkašâni

Fr.: supergalactique   

Of or pertaining to a system composed of nearby groups and clusters of galaxies in the → local Universe. Se also → galaxy cluster.

super-; → galactic.

supergalactic coordinate system
  راژمان ِ هماراهای ابرکهکشانی   
râžmân-e hamârâhâ-ye abarkahkašâni

Fr.: système des coordonnées supergalactiques   

A spherical → coordinate system in which the → equator is the → supergalactic plane. Supergalactic longitude, SGL, is measured → counterclockwise from direction l = 137.37 deg, b = 0 deg (between 0 and 360 deg). The zero point for supergalactic longitude is defined by the intersection of this plane with the → Galactic plane. In the → equatorial coordinate system (J2000) this is approximately 2.82 h, +59.5 deg. Supergalactic latitude, SGB, is measured from the supergalactic plane, positive northward and negative southward. The North Supergalactic Pole (SGB=90 deg) lies at galactic coordinates l = 47.37 deg, b = +6.32 degrees, corresponding to the equatorial coordinate system (J2000) 18.9 h, +15.7 deg.

supergalactic; → coordinate; → system.

supergalactic latitude
  ورونای ِ ابرکهکشانی   
varunâ-ye abarkahkašâni

Fr.: latitude supergalactique   

supergalactic coordinate system.

supergalactic; → latitude.

supergalactic longitude
  درژنای ِ ابرکهکشانی   
derežnâ-ye abarkahkašâni

Fr.: longitude supergalactique   

supergalactic coordinate system.

supergalactic; → longitude.

supergalactic plane
  هامن ِ ابرکهکشانی   
hâmon-e abarkahkašâni

Fr.: plan supergalactique   

The symmetry plane of the → Local Supercluster, where density of galaxies in our environment is the largest. The plane passes through the → Virgo cluster of galaxies, about which many of the brightest galaxies in the sky are concentrated. The supergalactic plane was recognized by Gérard de Vaucouleurs (1918-1995) in 1953 from the  → Shapley-Ames catalogue.

supergalactic; → plane.

warm-hot intergalactic medium
  مدیم ِ اندر-کهکشانی ِ گرم-داغ   
madim-e andar-kahkašâni garm-dâq

Fr.: milieu intergalactique chaud   

The space containing a cluster of galaxies filled with a tenuous gas of temperature 105 to 107 K and density 10-6 to 10-4 cm-3. WHIM has been continuously shock-heated during the process of structure formation. It is so highly ionized that it can only absorb or emit far-ultraviolet and soft X-ray photons, primarily at spectral lines of highly ionized C, O, Ne, and Fe. WHIM is thought to be the main reservoir of missing baryons.

warm; → hot; → intergalactic medium.

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