A statistical study of high coronal densities from X-ray line-ratios of Mg XI
A statistical study of high coronal densities from X-ray line-ratios of Mg XI
- Neue Suche nach: Linford, G. A.
- Neue Suche nach: Lemen, J. R.
- Neue Suche nach: Strong, K. T.
- Neue Suche nach: Linford, G. A.
- Neue Suche nach: Lemen, J. R.
- Neue Suche nach: Strong, K. T.
An X-ray line-ratio density diagnostic was applied to 50 Mg XI spectra of flaring active regions on the sun recorded by the Flat Crystal Spectrometer on the SMM. The plasma density is derived from R, the flux ratio of the forbidden to intercombination lines of the He-like ion, Mg XI. The R ratio for Mg XI is only density sensitive when the electron density exceeds a critical value (about 10 to the 12th/cu cm), the low-density limit (LDL). This theoretical value of the low-density limit is uncertain as it depends on complex atomic theory. Reported coronal densities above 10 to the 12th/cu cm are uncommon. In this study, the distribution of R ratio values about the LDL is estimated and the empirical values are derived for the 1st and 2nd moments of this distribution from 50 Mg XI spectra. From these derived parameters, the percentage of observations is derived which indicated densities above this limit.
Dokumentinformationen
A statistical study of high coronal densities from X-ray line-ratios of Mg XI
Advances in Space Research ; 11 , 1 19
1991-01-01
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Englisch
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