Spectral Line

(redirected from Emission line)
Also found in: Dictionary.
Related to Emission line: continuous spectrum, Line spectra

spectral line

[′spek·trəl ‚līn]
A discrete value of a quantity, such as frequency, wavelength, energy, or mass, whose spectrum is being investigated; one may observe a finite spread of values resulting from such factors as level width, Doppler broadening, and instrument imperfections. Also known as spectrum line.

Spectral Line


a thin line in an optical spectrum. Each such line can be characterized by a certain wavelength λ or frequency v = c/λ, where c is the speed of light. Spectral lines are observed in emission spectra as bright (colored) lines on a dark background and in absorption spectra as dark lines on a bright background. Each spectral line corresponds to a definite quantum transition in an atom, molecule, or crystal. Spectral lines are not strictly monochromatic: each one has a certain width Δλ.

References in periodicals archive ?
The quest to determine the nature of both dark matter and dark energy has led scientists to adopt new tracers of the large-scale structure of the Universe, such as emission line galaxies.
The solar-cycle variations in coronal emission line intensities (7) show that the intensity of the green line (Fe XIV) closely follows the sunspot number while that of the red line (Fe X) does not.
2]=30mm, wire 1 is emission line, wire 2 is disturbance line, where the excitation voltage of emission line is [V.
The LOD depends on the emission line selected for its calculation and the background noise standard deviation.
This scenario faces one potential problem--a puzzling third emission line, notes Cole Miller of the University of Maryland in College Park.
Spectral tables for four cosmically abundant elements (Ne, Mg, Si, and S) in the wavelength region of interest for the Chandra X-Ray Observatory, which is roughly 2 nm to 17 nm, have been critically compiled with partial support from the Chandra Emission Line Project.
The ration of the optical [SII] emmisson line to the Halpha emission line is the primary means to identify supernova remnants (SNR) and HII regions and confirm the radio identification of each source.
5 keV emission line is very difficult if not impossible to explain in terms of previously observed or predicted features from astronomical objects, and therefore a dark matter origin was suggested.
The observatory, which will consist of a telescope affixed with carbon, oxygen and nitrogen emission line detectors carried on board an Ultralong-Duration Balloon (ULDB) will not only map out the distribution of interstellar medium in the Milky Way, but also within its satellite galaxy - the Large Magellanic Cloud.
Astronomers detected this emission line in the Perseus galaxy cluster using both Chandra and XMM-Newton.
The emission line between H[beta] and H[gamma] visible during the early part of the outburst is probably the He II ionised helium line at 4686 [Angstrom].

Full browser ?