1) General: The process or fact of absorbing.
Fr.: bande d'absorption
1) A series of very closely spaced absorption lines in stellar spectra
resulting from the absorption of light by molecules. Bands caused by
titanium oxide (→ TiO bands) and carbon compounds occur
in the spectra of low temperature M and C stars.
Fr.: coefficient d'absorption
The fraction of normally incident light that is absorbed per unit path length or by a unit mass of absorbing medium.
Fr.: courbe d'absorption
A graphic representation of the amount of radiant energy absorbed by a material as a function of the wavelength.
Fr.: motif d'absorption
A dip in a spectrum indicating that light has been absorbed on the path from the emitting source to the observer. It may be a line, corresponding to a well-defined atomic or molecular transition, or a more complex feature whose physical origin is not necessarily understood.
Fr.: raie d'absorption
A dark line in the spectrum of a source produced by a lower temperature gas cloud lying between the source and the observer.
Fr.: nébuleuse par absorption, nébuleuse obscure
A dark cloud of dust and gas that absorbs light from and impedes the view of background stars; dark nebula.
Fr.: spectre d'absorption
A spectrum of absorption lines or bands, produced when light from a hot source, itself producing a continuous spectrum, passes through a cooler gas.
Fr.: absorption atmosphérique
The absorption of → electromagnetic radiation in the → atmosphere mainly by → water vapor, → carbon dioxide, and oxygen. The atmosphere introduces two more limiting factors in → remote sensing: → atmospheric scattering and → atmospheric turbulence.
discrete absorption component (DAC)
hamne-ye daršami-ye gosasté
Fr.: composante d'absorption discrète
The rapid, systematic changes in the absorption parts of the → P Cygni profiles of the ultraviolet → resonance lines (Si IV, C IV, and N V) observed in a majority of massive → hot stars. DACs are typically seen to accelerate to the → blue wing of the profile over a few days, becoming narrower as they approach the → terminal velocity.
Fr.: absorption d'avant-plan
Loss of radiant energy received from an astronomical object due to the presence of absorbing matter situated between the object and observer.
Fr.: absorption intergalactique
Fr.: absorption interne
Fr.: absorption interstellaire
The absorption of light from stars and other objects by intervening gas and dust in interstellar space.
mass absorption coefficient
hamgar-e daršm-e jermi
Fr.: coefficient d'absorption de masse
A measure of the rate of absorption of radiation, expressed as the linear absorption coefficient divided by the density of the medium through which radiation is passing.
A situation in which all of the energy of a photon is transferred to an atom, molecule, or nucleus.
Fr.: absorption sélective
Absorption which varies with the wavelength of radiation incident upon an absorbing substance.
The decrease in the radiation from a material caused by the absorption of a part of the radiation by the material itself.