تقرير
Coronal Elemental Abundance: New Results from Soft X-ray Spectroscopy of the Sun
العنوان: | Coronal Elemental Abundance: New Results from Soft X-ray Spectroscopy of the Sun |
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المؤلفون: | Narendranath, S., Sreekumar, P., Pillai, Netra S, Panini, S., Sankarasubramanian, K., Huovelin, Juhani |
سنة النشر: | 2020 |
المجموعة: | Astrophysics |
مصطلحات موضوعية: | Astrophysics - Solar and Stellar Astrophysics |
الوصف: | Elemental abundances in the solar corona are known to be different from those observed in the solar photosphere. The ratio of coronal to photospheric abundance shows a dependence on the first ionisation potential (FIP) of the element. We estimate FIP bias from direct measurements of elemental abundances from soft X-ray spectra using data from multiple space missions covering a range of solar activity levels. This comprehensive analysis shows clear evidence for a decrease in FIP bias around maximum intensity of the X-ray flare with coronal abundances briefly tending to photospheric values and a slow recovery as the flare decays. The departure from coronal abundances are larger for the low FIP elements Ca, Fe and Si than for S which have a mid FIP value. These changes in the degree of fractionation might provide inputs to model wave propagation through the chromosphere during flares. Comment: accepted for publication in Solar Physics |
نوع الوثيقة: | Working Paper |
DOI: | 10.1007/s11207-020-01738-5 |
URL الوصول: | http://arxiv.org/abs/2011.08584 |
رقم الأكسشن: | edsarx.2011.08584 |
قاعدة البيانات: | arXiv |
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