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SUMER measurement of the fex 3p43d 4D5/2,7/2 energy difference

Landi, E. ; Hutton, R. LU ; Brage, T. LU and Li, W. LU (2020) In Astrophysical Journal 902(1).
Abstract

Recent studies have shown that magnetic fields in the solar corona are strong enough to significantly mix the two 3p43d 4D5/2,7/2 levels in Cl-like Fe X. This mixing gives rise to a magnetically induced transition (MIT) component in the bright Fe X 257.3 Å line, commonly observed by current instrumentation, that can be used for coronal magnetic field diagnostics. This line, commonly observed by the still operational EIS spectrometer on board the Hinode satellite since 2007, opens a new window into the coronal magnetic field. However, the strength of this MIT transition depends on the square of the energy difference ΔE of the two 4D5 2,7 2 levels, so that an... (More)

Recent studies have shown that magnetic fields in the solar corona are strong enough to significantly mix the two 3p43d 4D5/2,7/2 levels in Cl-like Fe X. This mixing gives rise to a magnetically induced transition (MIT) component in the bright Fe X 257.3 Å line, commonly observed by current instrumentation, that can be used for coronal magnetic field diagnostics. This line, commonly observed by the still operational EIS spectrometer on board the Hinode satellite since 2007, opens a new window into the coronal magnetic field. However, the strength of this MIT transition depends on the square of the energy difference ΔE of the two 4D5 2,7 2 levels, so that an accurate determination of ΔE is of critical importance to accurately measure coronal magnetic field strengths. In the present work we present a new measurement of ΔE obtained determining the separation of the two component of the Fe X doublet close to 1603.3 Å from deep-exposure spectra of a quiescent streamer at the solar limb taken with the SUMER instrument on board SoHO. Our measurement of ΔE = 2.29 ± 0.50 cm-1 agrees with, and improves upon, an earlier measurements by Judge et al. by decreasing its uncertainty from 80% to approximately 20%, improving the attainable accuracy of magnetic field strength measurements obtainable with the Fe X 257.26 QA line.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Astrophysical Journal
volume
902
issue
1
article number
21
publisher
American Astronomical Society
external identifiers
  • scopus:85092665832
ISSN
0004-637X
DOI
10.3847/1538-4357/abb2a6
language
English
LU publication?
yes
id
df513e42-5487-42a4-bc4f-fb340c4427df
date added to LUP
2020-11-06 10:37:37
date last changed
2022-04-19 01:42:35
@article{df513e42-5487-42a4-bc4f-fb340c4427df,
  abstract     = {{<p>Recent studies have shown that magnetic fields in the solar corona are strong enough to significantly mix the two 3p<sup>4</sup>3d <sup>4</sup>D<sub>5</sub>/2,7/<sub>2</sub> levels in Cl-like Fe X. This mixing gives rise to a magnetically induced transition (MIT) component in the bright Fe X 257.3 Å line, commonly observed by current instrumentation, that can be used for coronal magnetic field diagnostics. This line, commonly observed by the still operational EIS spectrometer on board the Hinode satellite since 2007, opens a new window into the coronal magnetic field. However, the strength of this MIT transition depends on the square of the energy difference ΔE of the two <sup>4</sup>D<sub>5</sub> 2,7 <sub>2</sub> levels, so that an accurate determination of ΔE is of critical importance to accurately measure coronal magnetic field strengths. In the present work we present a new measurement of ΔE obtained determining the separation of the two component of the Fe X doublet close to 1603.3 Å from deep-exposure spectra of a quiescent streamer at the solar limb taken with the SUMER instrument on board SoHO. Our measurement of ΔE = 2.29 ± 0.50 cm<sup>-1</sup> agrees with, and improves upon, an earlier measurements by Judge et al. by decreasing its uncertainty from 80% to approximately 20%, improving the attainable accuracy of magnetic field strength measurements obtainable with the Fe X 257.26 QA line.</p>}},
  author       = {{Landi, E. and Hutton, R. and Brage, T. and Li, W.}},
  issn         = {{0004-637X}},
  language     = {{eng}},
  number       = {{1}},
  publisher    = {{American Astronomical Society}},
  series       = {{Astrophysical Journal}},
  title        = {{SUMER measurement of the fex 3p<sup>4</sup>3d <sup>4</sup>D<sub>5</sub>/2,7/<sub>2</sub> energy difference}},
  url          = {{http://dx.doi.org/10.3847/1538-4357/abb2a6}},
  doi          = {{10.3847/1538-4357/abb2a6}},
  volume       = {{902}},
  year         = {{2020}},
}