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arXiv 0911.1833astro-ph.SR
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宁静太阳上部过渡区的上升流

Upflows in the upper transition region of the quiet Sun

H. Tian, C. -Y. Tu, E. Marsch, J. -S. He, C. Zhou, L. Zhao

摘要:

我们调查的物理意义的显着的蓝移Ne VIII,这是观察到与安静的太阳网络连接(边界交叉点),通过数据分析相结合的无力场外推与EUV光谱观测。对于中纬度地区,我们重建了一个子区域的磁漏斗结构,显示在EIT-Fe 195微弱的发射。这个漏斗似乎由几个较小的漏斗组成,这些漏斗起源于网络通道,随着高度的增加而扩大,最后合并成一个单一的宽阔的开放区域。然而,Ne VIII的大蓝移通常与开放领域无关,但似乎与闭合磁回路的腿。此外,在大多数情况下,在两个漏斗形回路腿中发现显著的上升流。这些准稳定的上升流被认为是日冕环的物质供应的标志,而不是太阳风。我们的观测结果还表明,在许多情况下,上过渡区(TR)的上升流和中TR的下降流是不完全共空间的。基于这些新的观测结果,我们提出了冕洞和宁静太阳中不同的TR结构。

英文摘要:

We investigate the physical meaning of the prominent blue shifts of Ne VIII, which is observed to be associated with quiet-Sun network junctions (boundary intersections), through data analyses combining force-free-field extrapolations with EUV spectroscopic observations. For a middle-latitude region, we reconstruct the magnetic funnel structure in a sub-region showing faint emission in EIT-Fe 195. This funnel appears to consist of several smaller funnels that originate from network lanes, expand with height and finally merge into a single wide open-field region. However, the large blue shifts of Ne VIII are generally not associated with open fields, but seem to be associated with the legs of closed magnetic loops. Moreover, in most cases significant upflows are found in both of the funnel-shaped loop legs. These quasi-steady upflows are regarded as signatures of mass supply to the coronal loops rather than the solar wind. Our observational result also reveals that in many cases the upflows in the upper transition region (TR) and the downflows in the middle TR are not fully cospatial. Based on these new observational results, we suggest different TR structures in coronal holes and in the quiet Sun.

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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