Doppler broadening(redirected from Doppler profile)
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Doppler broadening(dop -ler) Broadening of spectral lines due to the random motion of emitting or absorbing atoms. As a result of the Doppler effect, atoms moving away from the observer show lines with a slight shift to longer wavelengths; atoms moving toward the observer show a slight shift to shorter wavelengths. The overall effect is that the line is broader than the natural width (determined by quantum mechanical uncertainty).
The motion of the atoms may be due to thermal motion, in which case the effect is larger for lighter atoms. Turbulence of stellar material, rapid rotation of a star, or an expanding stellar atmosphere can also produce Doppler broadening. See also line broadening.