The Ne VII 465.22 Å to Ca IX 466.23 Å Intensity Ratio Abundance Diagnostic in Solar Observations
Abstract
The Ne VII 465.22 Å, and the Ca IX 466.23 Å, lines appear side by side in spectra of solar atmosphere regions. Although the two ions are formed at nearly the same temperature, the relative intensities of the two lines show great variations from typical cases where Ne VII 465.23 Å is 20-30 times stronger than Ca IX 466.23 Å to spectra where the two lines are almost equal. The relative Ne VII/Ca IX intensity variation is correlated with the presence of the first ionization potential effect on elemental abundances in the outer solar atmosphere. Using published observational results, we derive the abundances of a number of regions and show that on occasion the enrichment of Ca in the solar atmosphere exceeds a factor of 30.
- Publication:
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The Astrophysical Journal
- Pub Date:
- December 2011
- DOI:
- 10.1088/0004-637X/742/2/71
- Bibcode:
- 2011ApJ...742...71W
- Keywords:
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- Sun: abundances;
- Sun: activity;
- Sun: UV radiation