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arXiv 1402.4903astro-ph.SR
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用HI帕邢线偏振光谱观测诊断色球喷流的磁场和电场

Diagnosis of Magnetic and Electric Fields of Chromospheric Jets through Spectropolarimetric Observations of HI Paschen Lines

Tetsu Anan, Roberto Casini, Kiyoshi Ichimoto

摘要:

磁场控制着太阳大气外层的等离子体动力学,而作用于穿过磁场的中性原子的电场使我们能够研究等离子体中中性原子和离子之间的动力学耦合。为了测量色球喷流的磁场和电场,2012年5月5日,利用日本飞田天文台的无顶太阳望远镜的分光偏振计观测了发生在太阳边缘的中性氢的帕邢系的全斯托克斯光谱。首先,我们只考虑了磁场对氢能级的能量结构和极化的影响,对斯托克斯光谱进行了反演。没有发现明确的证据表明,电场的影响,在所观察到的斯托克斯配置文件,然后,我们估计了这些领域的上限,通过计算的极化程度下的磁场配置在第一步中得到的,与额外存在的垂直(洛伦兹型)电场的强度变化。推断的磁场在天空平面(POS)上的方向大致与活动区域喷流和浪涌对齐,浪涌的磁场强度在10 G < B < 640 G的范围内。使用70,200,和600 G的磁场强度,我们得到的上限为可能的电场为0.04,0.3,和0.8 V/cm,分别。由于从洛伦兹电场的这些上限导出的中性氢原子穿过磁场的运动速度远低于由多普勒频移测量的垂直于磁场的等离子体的体速度,因此我们得出结论,中性原子在浪涌中必须高度冻结到磁场。

英文摘要:

Magnetic fields govern the plasma dynamics in the outer layers of the solar atmosphere, and electric fields acting on neutral atoms that move across the magnetic field enable us to study the dynamical coupling between neutrals and ions in the plasma. In order to measure the magnetic and electric fields of chromospheric jets, the full Stokes spectra of the Paschen series of neutral hydrogen in a surge and in some active region jets that took place at the solar limb were observed on May 5, 2012, using the spectropolarimeter of the Domeless Solar Telescope at Hida observatory, Japan. First, we inverted the Stokes spectra taking into account only the effect of magnetic fields on the energy structure and polarization of the hydrogen levels. Having found no definitive evidence of the effects of electric fields in the observed Stokes profiles, we then estimated an upper bound for these fields by calculating the polarization degree under the magnetic field configuration derived in the first step, with the additional presence of a perpendicular (Lorentz type) electric field of varying strength. The inferred direction of the magnetic field on the plane of the sky (POS) approximately aligns to the active region jets and the surge, with magnetic field strengths in the range 10 G < B < 640 G for the surge. Using magnetic field strengths of 70, 200, and 600 G, we obtained upper limits for possible electric fields of 0.04, 0.3, and 0.8 V/cm, respectively. Because the velocity of neutral atoms of hydrogen moving across the magnetic field derived from these upper limits of the Lorentz electric field is far below the bulk velocity of the plasma perpendicular to the magnetic field as measured by the Doppler shift, we conclude that the neutral atoms must be highly frozen to the magnetic field in the surge.

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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