Forward Modeling of Solar Coronal Magnetic Field Measurements Based on a Magnetic-field-induced Transition in Fe X. (arXiv:2107.11783v2 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Chen_Y/0/1/0/all/0/1">Yajie Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_W/0/1/0/all/0/1">Wenxian Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tian_H/0/1/0/all/0/1">Hui Tian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_F/0/1/0/all/0/1">Feng Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bai_X/0/1/0/all/0/1">Xianyong Bai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_Y/0/1/0/all/0/1">Yang Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_Z/0/1/0/all/0/1">Zihao Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_X/0/1/0/all/0/1">Xianyu Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Deng_Y/0/1/0/all/0/1">Yuanyong Deng</a>

It was recently proposed that the intensity ratios of several extreme
ultraviolet spectral lines from the Fe X ion can be used to measure the solar
coronal magnetic field based on the magnetic-field-inducedtransition (MIT)
theory. To verify the suitability of this method, we performed forward
modelingwith a three-dimensional radiation magnetohydrodynamic model of a solar
active region. Intensities of several spectral lines from Fe X were synthesized
from the model. Based on the MIT theory, intensity ratios of the MIT line Fe X
257 A to several other Fe X lines were used to derive the magnetic field
strengths, which were then compared with the field strengths in the model. We
also developed a new method to simultaneously estimate the coronal density and
temperature from the Fe X 174/175 and 184/345 A line ratios. Using these
estimates, we demonstrated that the MIT technique can provide reasonably
accurate measurements of the coronal magnetic field in both on-disk and
off-limb solar observations. Our investigation suggests that a spectrometer
that can simultaneously observe the Fe X 174, 175, 184, 257, and 345 A lines
and allow an accurate radiometric calibration for these lines is highly desired
to achieve reliable measurements of the coronal magnetic field. We have also
evaluatedthe impact of the uncertainty in the Fe X 3p4 3d 4D5/2 and 4D7/2
energy difference on the magnetic field measurements.

It was recently proposed that the intensity ratios of several extreme
ultraviolet spectral lines from the Fe X ion can be used to measure the solar
coronal magnetic field based on the magnetic-field-inducedtransition (MIT)
theory. To verify the suitability of this method, we performed forward
modelingwith a three-dimensional radiation magnetohydrodynamic model of a solar
active region. Intensities of several spectral lines from Fe X were synthesized
from the model. Based on the MIT theory, intensity ratios of the MIT line Fe X
257 A to several other Fe X lines were used to derive the magnetic field
strengths, which were then compared with the field strengths in the model. We
also developed a new method to simultaneously estimate the coronal density and
temperature from the Fe X 174/175 and 184/345 A line ratios. Using these
estimates, we demonstrated that the MIT technique can provide reasonably
accurate measurements of the coronal magnetic field in both on-disk and
off-limb solar observations. Our investigation suggests that a spectrometer
that can simultaneously observe the Fe X 174, 175, 184, 257, and 345 A lines
and allow an accurate radiometric calibration for these lines is highly desired
to achieve reliable measurements of the coronal magnetic field. We have also
evaluatedthe impact of the uncertainty in the Fe X 3p4 3d 4D5/2 and 4D7/2
energy difference on the magnetic field measurements.

http://arxiv.org/icons/sfx.gif