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: 466 Search : pH
hydrography
  آب‌نگاری   
âbnegâri (#)

Fr.: hydrographie   

The study, measurement, and description of depths and currents in open seas, lakes, estuaries, and rivers.

hydro- + → -graphy.

hydrosphere
  آب‌سپهر   
âbsepehr (#)

Fr.: hydrosphère   

A term denoting the water portion of the Earth's surface.

hydro-; → sphere.

hygrograph
  نم‌نگار   
namnegâš (#)

Fr.: hygrographe   

An instrument that records the hygrometer's measure of water vapor.

hygro- + → -graph.

Imaging Atmospheric Cherenkov Technique (IACT)
  تشنیک ِ تصویرگری ِ چرنکوف ِ جوی   
tašnik-e tasvirgiri-ye Čerenkov-e javvi

Fr.: téchnique d'imagerie Čerenkov atmosphérique   

The method used to detect very brief flashes of → Cherenkov radiation generated by the → cascade shower of → relativistic charged particles produced when a very high-energy → gamma ray (in the range 50 GeV to 50 TeV) strikes the atmosphere at a typical altitude of 10 km. Owing to this technique, it possible to discriminate cosmic gamma rays from the cosmic ray background and to determine their energy and source direction. More specifically, the incoming gamma-ray photon undergoes → pair production in the vicinity of the nucleus of an atmospheric molecule. The electron-positron pairs produced are of extremely high energy and immediately radiate in a → bremsstrahlung process. This radiation is itself extremely energetic, with many of the photons undergoing further pair production. A cascade of charged particles ensues which, due to its extreme energy, produces a flash of Cherenkov radiation lasting between 5 and 20 nano-seconds. The total area on the ground illuminated by this flash corresponds to many hundreds of square meters, which is why the effective area of IACT telescopes should be large.

imaging; → atmospheric; → Cherenkov; → technique.

in phase
  هم‌فاز   
hamfâz (#)

Fr.: en phase   

The condition which exists when two waves of the same frequency pass through their maximum and minimum values in a correlated or synchronized way.

in; → phase.

Hamfâz, from ham- "together," → com- + fâzphase.

infosphere
  ازداسپهر   
azdâsepehr

Fr.: infosphère   

The global network of all the world's communications, databases, and sources of information.

information; → sphere.

initial phase angle
  زاویه‌ی ِ فاز ِ آغازین   
zâviye-ye fâz-e âqâzin

Fr.: angle de phase initial   

The value of the phase corresponding to the origin of time. Same as the → epoch angle.

initial; → phase; → angle.

INPOP ephemerides
  روزیجهای ِ INPOP   
ruzijhâ-ye INPOP

Fr.: éphémérides INPOP   

A dynamical model developed in France since 2003 which calculates the motion of → Solar System bodies with the highest accuracy. It integrates data obtained by NASA and ESA space missions. See, for example, A. Fienga et al. 2011, arXiv:1108.5546.

INPOP, short for Intégration Numérique Planétaire de l'Observatoire de Paris; → ephemerides.

internal photoelectric effect
  اسکر ِ شید-برقی ِ درونی   
oskar-e šid-barqi-ye daruni

Fr.: effet photoélectrique interne   

The → photoelectric effect whereby photons absorbed by a solid (→ semiconductor) raise electrons from a lower to a higher → energy level (from → valence band to → conduction band). See also → external photoelectric effect.

internal; → photoelectric; → effect.

ionosphere
  یون‌سپهر   
yonsepehr (#)

Fr.: ionosphère   

The region of the Earth's upper atmosphere containing a small percentage of free electrons and ions produced by photoionization of the constituents of the atmosphere by solar ultraviolet radiation.

ion + → sphere.

iris diaphragm
  میان‌بند ِ تیتکی، ~ تیتک‌وار   
miyânband-e titaki, ~ titakvâr

Fr.: diaphragme iris   

A mechanical device, consisting of thin overlapping plates, designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light allowed through.

iris; → diaphragm.

isomorphism
  ایزو-ریخت‌مندی   
izo-rixtmandi

Fr.: isomorphisme   

A one-to-one → mapping between two → sets, which preserves the relations existing between elements in its → domain. An isomorphism is a → bijective morphism.

iso-; → morphism.

isoneph
  ایزو-ابر   
izoabr

Fr.: isonèphe   

A line drawn through all points on a weather map having the same amount of → cloud cover.

From Gk. → iso- + nephos "cloud," cognate with Pers. nam "humidity, moisture;" Av. napta- "moist," nabās-câ- "cloud," nabah- "sky;" Skt. nábhas- "moisture, cloud, mist;" L. nebula "mist," nimbus "rainstorm, rain cloud;" O.H.G. nebul; Ger. Nebel "fog;" O.E. nifol "dark;" from PIE *nebh- "cloud, vapor, fog, moist, sky."

Izoabr, from izo-, → iso-, + abr → cloud.

isophotal
  ایزوشیدی   
izošidi

Fr.: isophotal   

Of or relating to → isophotes.

isophote; → -al.

isophotal radius
  شعاع ِ ایزوشیدی   
šo'â'-e izošidi

Fr.: rayon isophotal   

The size attributed to a galaxy corresponding to a particular level of → surface brightness. The reason is that galaxies do not have sharp edges.

isophotal; → radius.

isophote
  ایزوشید   
izošid

Fr.: isophote   

A line joining points with the same surface brightness on a plot or in image of a celestial object such as a nebula or galaxy.

Isophote, from → iso- + a combining form of Gk. phos (gen. photos) "light."

Izošid, from izo-, → iso-, + šid "light, sunlight," from Mid.Pers. šêt "shining, radiant, bright;" Av. xšaēta- "shining, brilliant, splendid, excellent."

Josephson effect
  ا ُسکر ِ جوزفسون   
oskar-e Josephson

Fr.: effet Josephson   

A quantum mechanical → tunnel effect allowing the flow of a continuous current across two weakly coupled → superconductors which are separated by a very thin insulating barrier.

Named after the British physicist Brian David Josephson, who predicted the existence of the effect in 1962; → effect.

Josephson junction
  جوهه‌ی ِ جوزفسون   
juhe-ye Josephson (#)

Fr.: jonction Josephson   

A type of electronic circuit involving → Josephson effect, capable of switching at very high speeds when operated at temperatures approaching → absolute zero.

Josephson effect; → junction.

Jupiter's atmosphere
  جو ِ هرمز، هواسپهر ِ ~   
javv-e Hormoz, havâsepehr-e ~

Fr.: atmosphère de Jupiter   

The gaseous envelope surrounding Jupiter. It is about 90% → hydrogen and 10% → helium (by numbers of atoms, 75/25% by mass) with traces of → methane, → water, and → ammonia. This is very close to the composition of the primordial → solar nebula from which the entire solar system was formed. Saturn has a similar composition, but Uranus and Neptune have much less hydrogen and helium. The outermost layer is composed primarily of ordinary → molecular hydrogen and helium. Visually, Jupiter is dominated by two atmospheric features; a series of ever-changing atmospheric cloud bands arranged parallel to the equator and an oval atmospheric blob called the → Great Red Spot.

Jupiter; → atmosphere.

lexicography
  واژه‌نگاری   
vâženegâri

Fr.: lexicographie   

A branch of → linguistics that deals with the principle and methods of writing dictionaries.

lexicology; → -graphy.

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