Laboratory Study of the Diagnostic Utility of the 3C/3D Line Ratio in Fe XVII
Fe XVII x-ray emission is present, in a multitude of sources, such as the corona of the Sun, Capella, and Procyon. Two of the strongest lines observed in these spectra are the resonance and intercombination lines located at 15.01 and 15.26 {angstrom}, respectively. As part, of the laboratory astrophysics program at the electron beam ion traps EBIT-I and EBIT-II located at the Lawrence Livermore National Laboratory we have measured this line ratio for the case where the relative abundance of Fe XVI to Fe XVII is {approx} 1. Our results show that an Fe XVI innershell satellite line coincides with the intercombination line and can significantly reduce the relative intensity, R, of the resonance to intercombination line. The fact that the apparent, relative intensity of the resonance and intercombination line in Fe XVII is sensitive to the strength of an Fe XVI innershell satellite, and therefore, the relative abundance of Fe XVI to Fe XVII, makes the line ratio a diagnostic of temperature, and explains the anomalously low ratios observed in the solar and stellar coronae.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15002779
- Report Number(s):
- UCRL-JC-147249; TRN: US0402363
- Resource Relation:
- Conference: Laboratory Astrophysics Workshop, NASA Ames, Moffett Field, CA (US), 05/01/2002--05/03/2002; Other Information: PBD: 18 Jun 2002
- Country of Publication:
- United States
- Language:
- English
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