Abundances from SMM spectroscopic observations for non-flaring coronal plasma
Abstract
Plots of the Emission Measure vs. Temperature are used to look for deviations from the ``standard'' coronal abundance values for Oxygen, Neon, and Magnesium. The fluxes of three strong, relatively simple soft X-ray emission lines (O VIII at 18.97 Angstroms, Ne IX at 13.45 Angstroms, and Mg XI at 9.17 Angstroms) from spectra taken of quiescent active regions are analyzed. For four of the active regions investigated, the ``standard'' values of the abundances seem appropriate but, in the cases of four others variations from these values are required. The data indicate that the most likely source of these differences is a variation of the Neon abundance.
- Publication:
-
Advances in Space Research
- Pub Date:
- July 1995
- Bibcode:
- 1995AdSpR..15g..77S
- Keywords:
-
- Abundance;
- Hydrogen;
- Magnesium;
- Neon;
- Oxygen;
- Solar Corona;
- Variations;
- X Ray Astronomy;
- X Ray Spectra;
- Astronomical Spectroscopy;
- Electron Energy;
- Solar Maximum Mission;
- Solar Spectrometers;
- Solar Temperature;
- Space Plasmas;
- Solar Physics