core profile farâpâl-e maqzé Fr.: profil de cœur A → profile representing the number density of stars in the → core of a galaxy. |
density profile farâpâl-e cagâli Fr.: profile de densité 1) A → profile representing the
→ density of a quantity. |
Doppler profile farâpâl-e Doppler Fr.: profil Doppler The shape of the spectral line resulting from the Doppler broadening. → Doppler effect; → profile. |
Gaussian profile farâpâl-e Gaussi Fr.: profile gaussien The shape of a curve representing a normal distribution. |
instrumental profile 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 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. |
line profile farâpâl-e xatt Fr.: profil de raie The representation of a spectral line as produced by an observing instrument. |
line profile variability (LPV) 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 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. |
mean profile farâpâl-e miyângin Fr.: profil moyen The shape of a pulsar's pulse as determined by averaging several pulses. |
P Cygni profile 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 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 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. |
Sersic profile 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/R_{e})^{1/n}. The constant b is chosen such that R_{e} 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 farâpâl-e tondâ Fr.: profil de vitesse A plot of the fluid velocity as a function of position. |
Voigt profile 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. |