An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 8 Search : correction
bolometric correction
  ارشایش ِ تاوسنجی، ~ تاوسنجیک   
aršâyeš-e tâvsanji, ~ tâvsanjik

Fr.: correction bolométrique   

The difference between the → visual magnitude and → bolometric magnitude.

bolometric; → correction.

correction
  ارشایش   
aršâyeš

Fr.: correction   

1) The act or process of correcting.
2) A quantity added to a calculated or observed value to obtain the true value.
3) Something that is substituted or proposed for what is wrong or inaccurate.

Noun form of → correct.

extinction correction
  ارشایش ِ خاموشی   
aršâyeš-e xâmuši

Fr.: correction d'extinction   

In → photometric calibration, the correction for energy loss undergone by radiation due to the → atmospheric extinction. Extinction correction is done using → standard stars observed at different → airmasses.

extinction; → correction.

ionization correction factor (ICF)
  کروند ِ ارشایش ِ یونش   
karvand-e aršâyeš-e yoneš

Fr.: facteur de correction d'ionisation   

A quantity used in studies of → emission nebulae to convert the → ionic abundance of a given chemical element to its total → elemental abundance. The elemental abundance of an element relative to hydrogen is given by the sum of abundances of all its ions. In practice, not all the ionization stages are observed. One must therefore correct for unobserved stages using ICFs. A common way to do this was to rely on → ionization potential considerations. However, → photoionization models show that such simple relations do not necessarily hold. Hence, ICFs based on grids of photoionization models are more reliable. Nevertheless here also care should be taken for several reasons: the atomic physics is not well known yet, the ionization structure of a nebula depends on the spectral energy distribution of the stellar radiation field, which differs from one model to another, and the density structure of real nebulae is more complicated than that of idealized models (see, e.g., Stasińska, 2002, astro-ph/0207500, and references therein).

ionization; → correction; → factor.

K correction
  ارشایش ِ K   
aršâyeš-e K

Fr.: correction K   

A → color index correction applied to the photometric magnitudes and colors of a distant galaxy to compensate for the "reddening" of the galaxy due to → cosmological redshift. K correction is intended to derive the magnitudes in the → rest frame of the galaxy. Typically it is given as K(z) = az + bz2, where a and b depend on galaxy types. Conversely, one may deduce the redshift of a galaxy by its colors and a K-correction model.

The term K correction, probably stems from the K-term used by C. W. Wirtz (1918, Astron. Nachr. 206, 109), where K stands for Konstante, the German word for constant. The K-term was a constant offset in the redshift applied to diffuse nebulae in that epoch (source: A. L. Kinney, 1996, ApJ 467, 38); → correction.

Malmquist correction
  ارشایش ِ مالمکوییست   
aršâyeš-e Malmquist

Fr.: correction de Malmquist   

A correction introduced into star counts distributed by apparent magnitude.

Malmquist bias; → correction.

Rydberg correction
  ارشایش ِ رودبَری   
aršâyeš-e Rydberg

Fr.: correction de Rydberg   

A term inserted into a formula for the energy of a single electron in the outermost shell of an atom to take into account the failure of the inner electron shells to screen the nuclear charge completely.

rydberg; → correction.

wavefront correction
  ارشایش ِ پیشان ِ موج   
aršâyeš-e pišân-e mowj

Fr.: correction de front d'onde   

In → adaptive optics, eliminating the effects of atmospheric turbulence on the wavefront of the object being observed. → wavefront distortion.

wavefront; → correction.