Solar observations and atomic data for the 3s2 1s0-3s3p 3P1 transition in S V
Abstract
High resolution solar observations of the S v intersystem line at 1199.18 A are available from Skylab. This line is potentially useful as a density diagnostic for high density plasmas expected in solar flares. S v lines are also prominent in solar spectra at wavelengths below 1000 A. Collision strengths and radiative decay rates are calculated for levels of the configurations 3 s2, 3s3p, 3p2, and 3s3d. Level populations for the five lowest energy levels have been calculated as a function of electron density. These calculations are carried out assuming the temperature at which S v is most abundant in solar plasmas. The calculated population of the 3s3p 3P1 level reaches a pseudo-Boltzmann equilibrium at a density which is about five times higher than is derived from solar spectra and previous density determinations. It is believed that the discrepancy is due to a significant contribution from resonances to the 3s2-3s3p 3P excitation rate coefficient. It is suggested that the contribution of the resonances to the S v excitation rate coefficient can be estimated from a comparison of the experimental results and the theoretical calculations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1981
- DOI:
- 10.1086/159431
- Bibcode:
- 1981ApJ...250..799F
- Keywords:
-
- Atomic Energy Levels;
- Electron Transitions;
- Resonance Lines;
- Solar Spectra;
- Ultraviolet Spectra;
- Electron Density Profiles;
- Skylab Program;
- Solar Flares;
- Solar Wind;
- Ultraviolet Astronomy;
- Solar Physics