Fe VII Emission Lines in the Wavelength Range 193-197 Å
Abstract
The identifications of Fe VII emission lines in the wavelength range 193-197 Å are discussed in the light of new measurements of laboratory spectra and atomic data calculations. This region is of importance to studies of solar spectra from the EUV Imaging Spectrometer (EIS) on board the Hinode spacecraft, which has its peak sensitivity at these wavelengths. Ten lines are measured, arising from seven fine structure levels in the 3p53d3 configuration. Two lines have not previously been reported and lead to new experimental energies for the ${({a}^{2}D)}^{3}{F}_{\mathrm{2,3}}$ levels. Updated experimental energies are obtained for the remaining levels. The new atomic model is used to compute theoretical values for the two density diagnostic ratios λ196.21/λ195.39 and λ196.21/λ196.06, and densities are derived from EIS spectra of coronal loop footpoints.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2021
- DOI:
- 10.3847/1538-4357/abd39b
- arXiv:
- arXiv:2012.08027
- Bibcode:
- 2021ApJ...908..104Y
- Keywords:
-
- Atomic spectroscopy;
- Spectroscopy;
- Line intensities;
- Solar extreme ultraviolet emission;
- Solar transition region;
- 2099;
- 1558;
- 2084;
- 1493;
- 1532;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted by ApJ