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: 1358
cosmic web
  وپ ِ کیهانی   
vap-e keyhâni

Fr.: toile cosmique   

The entire, large-scale structure of the → Universe in which → galaxy clusters are connected by → cosmic filaments (made up of → dark matter and → baryons) in a spongelike geometry, while the low-density → voids are connected to each other by low-density tunnels. The term cosmic web was coined in 1996 by J. Richard Bond et al. (Nature, 380, 603).

cosmic; → web.

cosmic-ray burst
  بلک ِ پرتوهای ِ کیهانی   
belk-e partowhâ-ye keyhâni

Fr.: sursaut de rayons cosmiques   

An intense beam of cosmic rays coming from any direction on the sky, which originates outside the solar system.

cosmic; → ray; → burst.

cosmic-ray event
  رویداد ِ پرتوهای ِ کیهانی   
ruydâd-e partowhâ-ye keyhâni

Fr.: événement des rayons cosmiques, un cosmique   

Spurious signals in CCD frames caused by ionizing radiation which appear as a set of pixels with intense values sparsely scattered over the CCD frame. High energy particles generate muons, which deposit around 80 electrons per micron in silicon. With a collection depth of 10-20 microns, a cosmic-ray event is seen on a CCD frame as having a signal of up to a few thousand electrons, usually concentrated in one or two pixels. Although attributed to cosmic-ray hits, they may also be due to background terrestrial radiation.

cosmic rays; → event.

cosmic-ray ionization
  یونش ِ پرتوهای ِ کیهانی   
yoneš-e partowhâ-ye keyhâni

Fr.: ionisation par rayons cosmiques   

The ionization of → interstellar medium (ISM) gas by → cosmic rays. Cosmic rays are a primary source of ionization, competing with stellar → ultraviolet photons and → X-rays produced by embedded → young stellar objects. Cosmic rays play a key role in the chemistry and dynamics of the interstellar medium. The ionization fraction in turn drives the chemistry of → molecular clouds and controls the coupling of the gas with the Galactic → magnetic field. Moreover, cosmic rays represent an important source of → heating for → molecular clouds because the energy of primary and secondary electrons produced by the ionization process is in large part converted into heat by → inelastic collisions with ISM atoms and → molecules (see, e.g., Padovanit et al., 2009, arXiv:0904.4149).

cosmic; → ray; → ionization.

cosmic-ray shower
  تندبار ِ پرتوهای ِ کیهانی، رگبار ِ ~   
tondbâr-e partowhâ-ye keyhâni, ragbâr-e ~

Fr.: gerbe cosmique   

An extensive (many kilometres wide) → cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a → primary cosmic rays collides with atmospheric nuclei creating many → secondary cosmic rays. Also known as → air shower.

cosmic; → ray; → shower.

cosmo-
  کیهان-   
keyhân- (#)

Fr.: cosmo-   

Combining form of → cosmos.

cosmos.

cosmochemistry
  کیهان-شیمی   
keyhân-šimi

Fr.: cosmochimie   

The study of the chemical composition of the universe and the processes that produced those compositions. Cosmochemistry is an interdisciplinary science that overlaps with geochemistry, geology, astronomy, astrophysics, and geophysics.

cosmo-; → chemistry.

cosmogenic neutrino
  نوترینوی‌ ِ پرتو ِ کیهانی، ~ کیهانزاد   
notrino-ye partow-e keyhâni, ~ keyhânzâd

Fr.: neutrino cosmogénique   

A type of neutrino generated by → UHECRs during their journey from distant sources to the Earth. Also called → ultra high energy neutrino.

Constructed from cosmo-, from → cosmic rays + -genic, → cryogenic.

cosmogony
  کیهانزایش   
keyhânzâyeš

Fr.: cosmogonie   

A philosophical, religious, or mythical story of the creation or origin of the → Universe, usually referring to the → solar system.

From → cosmo- + -gony, from L. -gonia, from Gk. -goneia, from gonos, offspring; cf. Av. zan- "to bear, give birth to a child, be born," infinitive zizâite, zâta- "born," Pers. zâdan "give birth, be born", Skt. janati "begets, bears," Gk. gignesthai "to become, happen" L. gignere "to beget," gnasci "to be born," PIE base *gen- "to give birth, beget").

Keyhânzâyeš, from keyhân, → cosmo-, + zâyeš verbal noun from zâdan "be born; give birth," as above.

cosmography
  کیهاننگاری   
keyhânnegâri

Fr.: cosmographie   

The branch of → cosmology concerned with the dimensional structures of the → Universe and their measurement.

cosmo-; → -graphy.

cosmological
  کیهان‌شناختی، کیهان‌شناسیک   
keyhânšenâxti, keyhânšenâsik

Fr.: cosmologique   

Pertaining or relating to → cosmology.

cosmology; → -al.

cosmological constant
  پایای ِ کیهان‌شناسیک، ~ کیهان‌شناختی   
pâyâ-ye keyhânšenâsik, ~ keyhânšenâxti

Fr.: constante cosmologique   

A term introduced by Einstein into his gravitational → field equations in order to allow a solution corresponding to a → static Universe. The cosmological constant is physically interpreted as due to the → vacuum energy of quantized fields. See also → dark energy.

cosmological; → constant.

cosmological constant problem
  پراسه‌ی ِ پایای ِ کیهانشناختی   
parâse-ye pâyâ-ye keyhânšenâxti

Fr.: problème de la constante cosmologique   

The impressive discrepancy of about 120 orders of magnitude between the theoretical value of the → cosmological constant and its observed value. → Quantum field theory interprets the cosmological constant as the density of the → vacuum energy. This density can be derived from the maximum energy at which the theory is valid, i.e. the → Planck energy scale (1018 GeV). The theoretical vacuum → energy density is (1018 GeV)4 = (1027 eV)4 = 10112 erg cm-3. On the other hand, the observed vacuum energy density is estimated to be about (10-3 eV)4 = 10-8 erg cm-3. There is, therefore, a discrepancy of about 120 orders of magnitude.

cosmological; → constant; → problem.

cosmological distance
  دورای ِ کیهان‌شناسیک، ~ کیهان‌شناختی   
durâ-ye keyhânšenâsik, ~ keyhânšenâxti

Fr.: distance cosmologique   

The distance to a remote galaxy based on its redshift assuming that the redshift is caused by the → Doppler effect and reflects the general expansion of the Universe.

cosmological; → distance .

cosmological epoch
  زیمه‌ی ِ کیهانشناختی   
zime-ye keyhânšenâxti

Fr.: époque cosmologique   

cosmological; → epoch.

cosmological model
  مدل ِ کیهان‌شناسیک، ~ کیهان‌شناختی   
model-e keyhânšenâsik, ~ keyhânšenâxti

Fr.: modèle cosmologique   

A mathematical description of the Universe, based on observation, which tries to explain its current aspect, and to describe its evolution during time.

cosmological; → model.

cosmological principle
  پروز ِ کیهان‌شناسیک، ~ کیهان‌شناختی   
parvaz-e keyhânšenâsik, ~ keyhânšenâxti

Fr.: principe cosmologique   

The → hypothesis that on → large scales the → Universe is → isotropic and → homogeneous, that is, it appears the same at all places and, from any one place, looks the same in all directions. See also → perfect cosmological principle.

Introduced by E.A. Milne in 1933; → cosmological; → principle.

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.

cosmology
  کیهان‌شناسی   
keyhânšenâsi (#)

Fr.: cosmologie   

The science of the origin, structure, and evolution of the Universe including the origin of galaxies, the chemical elements, and matter.

Cosmology, from → cosmo- + → -logy.

Keyhânšenâsi, from keyhân, → cosmos, + šenâsi, → -logy.

cosmonaut
  کیهان نورد، فضا نورد   
keyhânnavard (#), fazânavard (#)

Fr.: cosmonaute, astronaute   

The Russian term for → astronaut.

Cosmonaut, from → cosmo- + naute, from Gk. nautes "sailor," from naus "ship" (cognate with Pers. nâv "ship," Av./O.Pers. *nāv-, O.Pers. nāviyā- "fleet," Skt. nau-, nava- "ship, boat," Gk. naus, neus, L. navis; PIE *nâu- "ship").

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