期刊
ASTROPHYSICAL JOURNAL
卷 916, 期 1, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.3847/1538-4357/ac01eb
关键词
-
资金
- National Science Foundation Major Research Instrument program [ATM-0421582]
The study reports spectropolarimetric observations of a supersonic downflow impacting the lower atmosphere within a large sunspot umbra, revealing high speed emission and absorption phenomena. Magnetic field strengths and temperatures were inferred from the observations, providing insights into the impact of the downflow on the sunspot atmosphere.
We report spectropolarimetric observations of a supersonic downflow impacting the lower atmosphere within a large sunspot umbra. This work is an extension of Schad et al. using observations acquired in the He i 10830 angstrom triplet by the Facility Infrared Spectropolarimeter. Downflowing material accelerating along a cooled coronal loop reaches peak speeds near 200 km s(-1) and exhibits both high speed emission and absorption within the umbra, which we determine to be a consequence of the strong height dependence of the radiatively controlled source function above the sunspot umbra. Strong emission profiles close to the rest wavelengths but with long redshifted tails are also observed at the downflow terminus. From the polarized spectra, we infer longitudinal magnetic field strengths of similar to 2.4 kG in the core portion of the He i strong emission, which we believe is the strongest ever reported in this line. Photospheric field strengths along the same line of sight are similar to 2.8 kG as inferred using the Ca i 10839 angstrom spectral line. The temperatures of the highest speed He i absorption and the near-rest emission are similar (similar to 10 kK), while a differential emission measure analysis using Solar Dynamics Observatory/Atmospheric Imaging Assembly data indicates significant increases in radiative cooling for temperatures between similar to 0.5 and 1 MK plasma associated with the downflow terminus. Combined we interpret these observations in the context of a strong radiative shock induced by the supersonic downflow impacting the low sunspot atmosphere.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据