论文标题
估计极性冠状孔边界处的离子温度
Estimating Ion Temperatures at the Polar Coronal Hole Boundary
论文作者
论文摘要
太阳能电晕中重离子（$ t_i $）的温度提供了有关百万度电晕加热机制的关键信息。但是，由于非热运动，工具限制以及冠状排放的光学薄质，$ T_I $的测量通常具有挑战性。我们介绍了$ t_i $的测量及其对极性冠状孔边界处离子电荷与质量比（$ z/a $）的依赖性，仅假设重离子具有相同的非热速度。为了改善$ z/a $覆盖范围并研究了仪器扩展的影响，我们使用了HINODE卫星的极端粉状成像光谱仪（EIS）的协调观察，并在板上的Solar和Heliosperic Octerveratis（Sumer sumer sumer radiation（Sumer）的太阳能紫外线测量值（SUMER）测量。我们发现，$ z/a $少于0.20或大于0.33的离子的$ t_i $远高于本地电子温度。我们运行了Alfvén波太阳模型现实时间，以研究沿视线（LOS）的光学薄排放的形成。模拟表明，沿LOS沿LOS的血浆大量运动拓宽了冠状孔中热发射线的宽度（例如Fe XII，Fe XIII）。我们讨论了可能影响$ t_i $测量的其他因素，包括一些明亮的Sumer线中的非高斯翅膀，可以通过双高斯或$κ$分布来安装。我们的研究证实了对冠状孔中重离子的优先加热，并对冠加热模型提供了新的限制。
The temperatures of the heavy ions ($T_i$) in the solar corona provide critical information about the heating mechanism of the million-degree corona. However, the measurement of $T_i$ is usually challenging due to the nonthermal motion, instrumental limitations, and the optically thin nature of the coronal emissions. We present the measurement of $T_i$ and its dependency on the ion charge-to-mass ratio ($Z/A$) at the polar coronal hole boundary, only assuming that heavy ions have the same nonthermal velocity. To improve the $Z/A$ coverage and study the influence of the instrumental broadening, we used a coordinated observation from the extreme-ultraviolet Imaging Spectrometer (EIS) on board the Hinode satellite and the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) on board the Solar and Heliospheric Observatory (SOHO). We found that the $T_i$ of ions with $Z/A$ less than 0.20 or greater than 0.33 are much higher than the local electron temperature. We ran the Alfvén Wave Solar Model-realtime to investigate the formation of optically thin emissions along the line of sight (LOS). The simulation suggested that plasma bulk motions along the LOS broaden the widths of hot emission lines in the coronal hole (e.g., Fe XII, Fe XIII). We discussed other factors that might affect the $T_i$ measurement, including the non-Gaussian wings in some bright SUMER lines, which can be fitted by a double-Gaussian or a $κ$ distribution. Our study confirms the preferential heating of heavy ions in coronal holes and provides new constraints on coronal heating models.
