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: 16 Search : profile
core profile
  فراپال ِ مغزه   
farâpâl-e maqzé

Fr.: profil de cœur   

A → profile representing the number density of stars in the → core of a galaxy.

core; → profile.

density profile
  فراپال ِ چگالی   
farâpâl-e cagâli

Fr.: profile de densité   

1) A → profile representing the → density of a quantity.
2) A → profile representing the distribution of stars as a function of their number in a region.

density; → profile.

Doppler profile
  فراپال ِ دوپلر   
farâpâl-e Doppler

Fr.: profil Doppler   

The shape of the spectral line resulting from the Doppler broadening.

Doppler effect; → profile.

Gaussian profile
  فراپال ِ گاؤسی   
farâpâl-e Gaussi

Fr.: profile gaussien   

The shape of a curve representing a normal distribution.

Gaussian; → profile.

instrumental profile
  فراپال ِ سازالی   
farâpâl-e sâzâli

Fr.: profil instrumental   

The shape of instrument's response to the input signal. The Fourier transform of the source function by the instrument function.

instrumental; → profile.

inverse P Cygni line profile
  فراپال ِ P Cygniی ِ وارون   
farâpâl-e P Cygni-ye vârun

Fr.: profil P Cygni inverse   

A line profile in which the emission is on the blue side of the absorption. It is usually interpreted as the redshift of the absorption component relative to emission lines, which necessitates infall of matter.

inverse; → P Cygni; → line; → profile.

line profile
  فراپال ِ خط   
farâpâl-e xatt

Fr.: profil de raie   

The representation of a spectral line as produced by an observing instrument.

line, → profile.

line profile variability (LPV)
  ورتندگی ِ فراپال ِ خط   
vartandegi-ye farâpâl-e xatt

Fr.: variabilité du profil de raie   

The change in the shape of a → spectral line over time. For instance, in → Wolf-Rayet stars the line profile varying on time-scales of minutes to hours is attributed to → microturbulence.

line; → profile; → variability.

Lorentzian profile
  فراپال ِ لورنتزی   
farâpâl-e Lorentzi

Fr.: profil lorentzien   

A spectral profile in which the intensity distribution follows a specific mathematical function (Lorentz or Cauchy probability). Compared to the normal or Gaussian profile, Lorentzian has a pointed peak and more important wings.

Lorentz; → profile.

mean profile
  فراپال ِ میانگین   
farâpâl-e miyângin

Fr.: profil moyen   

The shape of a pulsar's pulse as determined by averaging several pulses.

mean; → profile.

P Cygni profile
  فراپال ِ P Cygni   
farâpâl-e P Cygni

Fr.: profil P Cygni   

A feature in a stellar spectrum showing strong hydrogen and helium emission lines with absorption lines on their blueward wing. This line profile indicates a strong outflow of matter from a star. → inverse P Cygni line profile.

After → P Cygni star.

profile
  فراپال   
farâpâl

Fr.: profil   

A graph or drawing that shows the variation of one property (such as intensity), usually as ordinate, with respect to another property (such as wavelength). → line profile.

From It. profilo "a drawing in outline," from profilare "to draw in outline," from → pro- "forth" + filare "draw out, spin," from L.L. filare "to spin, draw out a line," from filum "thread," cognate with Pers. zeh "cord, string," → filament.

Farâpâl, from farâ-, → pro-, + pâl "thread, string," probably cognate with L. filum, as above.

profile fitting method
  روش ِ سزکرد ِ فراپال   
raveš-e sazkard-e farâpâl

Fr.: méthode de l'ajustement de profils   

A method of analysis in which the observed stellar image profiles or spectral line profiles are fitted by model profiles in order to study and derive some properties of the object.

profile; → fitting; → method.

Sersic profile
  فراپال ِ سرسیک   
farâpâl-e Sérsic

Fr.: profile de Sérsic   

A mathematical function that describes how the → intensity  I of a → galaxy varies with distance R from its center. It is given by: (dln I/dln R) = -(b/n)(R/Re)1/n. The constant b is chosen such that Re is the → effective radius; n is the Sérsic index. The Sérsic profile is a generalization of → de Vaucouleurs law. Setting n = 4 gives the de Vaucouleurs profile.

J. L. Sérsic, 1963, Boletin de la Asociacion Argentina de Astronomia, Vol. 6, p.41; → profile.

velocity profile
  فراپال ِ تندا   
farâpâl-e tondâ

Fr.: profil de vitesse   

A plot of the fluid velocity as a function of position.

velocity; → profile.

Voigt profile
  فراپال ِ فوکت   
farâpâl-e Voigt

Fr.: profil de Voigt   

A spectral profile in which a → spectral line is broadened by two types of mechanisms, one of which alone would produce a & rarr; Gaussian profile (usually, as a result of the → Doppler broadening), and the other would produce a → Lorentzian profile.

After Woldemar Voigt (1850-1919), a German physicist; → profile.