S XI Line Ratios in the Sun
Abstract
Recently, Conlon et al. (1992) used Aggarwal's (1986) R-matrix calculations of electron excitation rates for Si IX, Ca XV, and Fe XXI to interpolate atomic data for other C-like ions, including S XI. Here, the results of Conlon et al. are used to derive diagnostic line ratios for S XI, and the ratios are compared with solar flare observational data obtained with the S082A instrument aboard Skylab. The experimental ratios are generally much larger than those predicted by theory, probably because of blending of the S XI 215.97 A line with Ni XVII 215.91 A and S XI 190.37 A with an unidentified feature at a coincident wavelength. These observations indicate that photoexcitation of S XI by Fe XII 191.26 A is probably not an important process in the solar atmosphere under flare conditions.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1993
- DOI:
- 10.1086/173049
- Bibcode:
- 1993ApJ...413..826K
- Keywords:
-
- Electron Density (Concentration);
- Emission Spectra;
- Solar Flares;
- Solar Spectra;
- Electron Energy;
- Electron Transitions;
- Photoexcitation;
- Spectrum Analysis;
- Solar Physics;
- ATOMIC PROCESSES;
- SUN: FLARES