The formation of the Mg II resonance line wings in the solar atmosphere (II).
Abstract
Synthetic LTE profiles of the Mg II resonance lines computed for the HSRA, VAL, and 'Ca II and Mg II' model atmospheres are compared with profiles of the average quiet sun in the gamma wavelength range 2760-2820 A at the radial positions of 1.0, 0.6 + or - 0.06, and 0.43 + or - 0.01. The expression for the total opacity as a function of the height is derived; these opacity functions reproduce the observed local continuum intensities at gamma 2660 and 2940 and the adopted wavelength averaged limb darkening curve. The most appropriate value of the abundance of Mg and the factor applied to the collisional broadening is derived from the best fit of the calculated profiles; the comparison of the computed and observed profiles shows that none of the one-component static model atmospheres for the average quiet sun reproduces the center-to-limb variations for the central parts of the MG II profiles.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1980
- Bibcode:
- 1980A&A....90..231G
- Keywords:
-
- Magnesium;
- Solar Atmosphere;
- Solar Spectra;
- Line Spectra;
- Opacity;
- Solar Physics;
- Line Formation:Solar Atmosphere