Helium-like Argon Line Emission in Solar Flares
Abstract
Theoretical X-ray spectra of Ar XVII lines and Ar XVI satellites at ∼4 Å, derived from R-matrix code and other calculations, are compared with solar-flare observations obtained with the SMM Flat Crystal Spectrometer. There is good agreement between the observed line features and those in the theoretical spectra, and the comparison leads to best-fit values of electron temperature for the observed solar flares. We present wavelengths for the Ar XVII and some Ar XVI lines, measured from the observed spectra, which have better precision than previous values. In addition, the coronal Ar/S abundance is determined from the relative intensities of Ar XVII lines to those of nearby S XV transitions, and the value of this ratio is discussed in the light of previous work.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1993
- DOI:
- 10.1086/173495
- Bibcode:
- 1993ApJ...419..426P
- Keywords:
-
- ATOMIC DATA;
- ATOMIC PROCESSES;
- SUN: ABUNDANCES;
- SUN: FLARES;
- SUN: X-RAYS;
- GAMMA RAYS