Pressure broadening of CO and OCS spectral lines

1988 ◽  
Vol 40 (3) ◽  
pp. 205-220 ◽  
Author(s):  
J.-P. Bouanich ◽  
G. Blanquet
2005 ◽  
Vol 60 (10) ◽  
pp. 727-735
Author(s):  
Reda A. El-Koramy ◽  
Abd El-Halim A. Turky

Spectral analysis of the alkali metals is characterized by pressure profiles. In the present work an electric arc has been used to calibrate the half-width of the intensity used in the construction of the ArI natural line at 4300 Å with a trace of evaporated rubidium at pressures of 1, 2 and 3 atmospheres. The results agree well with those obtained by Kusch’s line absorption equation in an electric furnace in the point of view of impact approximation, showing that the widths of the lines have Lorentz shapes. It is found that a simple treatment can be given using the quasi-static approximation of pressure broadening developed by Unsöld. The agreement of the results is good only if the shifts are large. The study shows that the pressure line profile is made up of a sum of dispersion profiles and asymmetric terms which arise from interactions of quadratic Stark effect, commonly assumed to be the force in causing foreign gas broadening


1945 ◽  
Vol 68 (3-4) ◽  
pp. 78-93 ◽  
Author(s):  
Alexander Jabloński

1969 ◽  
Vol 182 (1) ◽  
pp. 24-38 ◽  
Author(s):  
Joel I. Gersten ◽  
Henry M. Foley

1988 ◽  
Vol 66 (4) ◽  
pp. 341-348
Author(s):  
M. A. Diaz ◽  
F. Palomares ◽  
J. Veguillas

An explicit spectral function for nonresonant transitions has been derived that includes pressure broadening, Doppler broadening, and diffusional narrowing. This has been accomplished through a kinetic-equation approach. The kinetic equation has been resolved by using an extension of the Bhatnagar–Gross–Krook collision model to inelastic collisions, characterized by two collision frequencies: one associated with elastic collisions and the other associated with inelastic ones. The high- and low-density limits have been discussed, and the standard formula for Debye relaxation has been reproduced. Finally, a discussion concerning the above aspects and their possible extensions has been included as well.


1980 ◽  
Vol 51 ◽  
pp. 213-224
Author(s):  
Åke Nordlund

AbstractThe results of numerical simulations of the solar granulation are used to investigate the effects on photospheric apectral lines of the correlated velocity and temperature fluctuations of the convective granular motions. It is verified that the granular velocity field is the main cause for the observed broadening and strengthening of photospheric spectral lines relative to values expected from pure thermal and pressure broadening. These effects are normally referred to as being due to “macro-turbulence” and “micro-turbulence”, respectively. It is also shown that the correlated temperature and velocity fluctuations produce a “convective blue shift” in agreement with the observed blue shift of photospheric spectral lines. Reasons are given for the characteristic shapes of spectral line bisectors, and the dependence of these shapes on line strength, excitation potential, and center to limb distance are discussed.


1950 ◽  
Vol 79 (4) ◽  
pp. 744-744 ◽  
Author(s):  
T. Holstein

2005 ◽  
Vol 19 (05) ◽  
pp. 239-247
Author(s):  
JIE-LI LIN ◽  
HONG LU

A series of relative errors ε of the pressure broadening coefficient γfit with respect to the real one γ0 from fitting overlapped spectrum which are composed of two lines with the Voigt profile, are deduced and analyzed in detail for different pressure ranges. ε is found to be related with the value of γ0 and the spectral center distance δυ0 of the two component spectral lines which are not resolved. The influence of δυ0, pressures P and γ0 on ε is discussed. This work can be taken as a useful reference for the analysis of the observed spectrum which is overlapped by two lines to achieve more precise results of γfit.


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