Phys.org August 2, 2024
When studying the solar spectrum, researchers often search for emission spectra of two iron ions, Fe IX and Fe X, which are useful for studying the sun’s outer atmosphere. However, both spectra contain emission lines that cannot be matched with known electron transitions, limiting the information which can be gathered from them. A team of researchers in the US (Columbia University, Lawrence Livermore National Laboratory, UC Berkeley) presented measurements made in the wavelength range 238–258 Å which helped them to identify the charge state associated with each of the observed lines. This wavelength range was of interest because it contained the Fe IX density diagnostic line was predicted to be one of the best density diagnostics of the solar corona, as well as the Fe X 257.26 Å magnetic-field-induced transition. They measured previously unidentified Fe X lines that will need to be added to CHIANTI and other spectroscopic databases… read more. Open Access TECHNICAL ARTICLE
Measuring emission lines in the sun’s corona. Credit: The European Physical Journal D, Volume 78, article number 99, 29 July 2024