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arXiv 2107.01015astro-ph.SR
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H Ⅰ和He II的Lyman- $α$线的偏振作为研究日冕的工具

The polarization of the Lyman-$α$ lines of H I and He II as a tool for exploring the solar corona

Supriya Hebbur Dayananda, Javier Trujillo Bueno, Ángel de Vicente, Tanausú del Pino Alemán

摘要:

近地空间天气是由日冕中磁自由能的快速释放驱动的。探测这一极热且稀薄的太阳大气层扩展区域需要模拟禁止和允许的日冕线的偏振。为此,必须开发有效的代码来计算从给定的三维日冕模型中出现的斯托克斯轮廓,并且应该考虑到磁场和非径向太阳风速度的存在所产生的对称性破缺。我们已经开发了这样一个工具,其目的是在理论上预测和解释在允许和禁止行的太阳日冕的分光偏振观测。在本文中,我们显示的线性极化信号的散射过程中产生的H I Ly- $α$线在1216 A和在He II Ly- $α$线在304 A使用三维日冕模型的预测科学公司的理论研究结果。这些谱线对于Hanle效应的开始具有非常不同的临界磁场(分别为53 G和850 G),以及对于由太阳风速度引起的多普勒效应具有不同的灵敏度。我们研究了在什么情况下,这些Ly- $α$线的散射极化的同时观测,可以促进在太阳日冕中的磁场和宏观速度的测定。

英文摘要:

The near-Earth space weather is driven by the quick release of magnetic free energy in the solar corona. Probing this extremely hot and rarified region of the extended solar atmosphere requires modeling the polarization of forbidden and permitted coronal lines. To this end, it is important to develop efficient codes to calculate the Stokes profiles that emerge from given three-dimensional (3D) coronal models, and this should be done taking into account the symmetry breaking produced by the presence of magnetic fields and non-radial solar wind velocities. We have developed such a tool with the aim of theoretically predicting and interpreting spectropolarimetric observations of the solar corona in permitted and forbidden lines. In this paper we show the results of a theoretical investigation of the linear polarization signals produced by scattering processes in the H I Ly-$α$ line at 1216 A and in the He II Ly-$α$ line at 304 A using 3D coronal models by Predictive Science Inc. These spectral lines have very different critical magnetic fields for the onset of the Hanle effect (53 G and 850 G, respectively), as well as different sensitivities to the Doppler effect caused by the solar wind velocities. We study under which circumstances simultaneous observations of the scattering polarization in these Ly-$α$ lines can facilitate the determination of magnetic fields and macroscopic velocities in the solar corona.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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