arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2004.06815astro-ph.SR
收藏

日冕热力学结构的层析重建和MHD模拟

Thermodynamic Structure of the Solar Corona: Tomographic Reconstructions and MHD Modeling

D. G. Lloveras, A. M. Vásquez, F. A. Nuevo, C. Mac Cormack, N. Sachdeva, W. Manchester, B. Van der Holst, R. A. Frazin

摘要:

利用层析重建和磁流体动力学模拟对静止内日冕($r<1.25 R_\odot$)电子密度和温度的全球三维结构进行了研究。我们使用差分发射测量层析成像(DEMT)和阿尔文波太阳模型(AWSoM),在他们的最新版本。两个目标的旋转选择从太阳活动周期(SC)23和24之间的太阳极小期和SC 24的下降阶段。我们报告的三维热力学结构的核心和外层的流光带,和高纬度冕洞(CH)的定量细节,所揭示的DEMT分析。我们报告的存在下,两种类型的结构内的流光带,循环温度随高度降低/增加(被称为下/上循环),首先在以前的DEMT研究报告。我们还估计了在日冕底部所需的热能通量,以保持这些结构的稳定,被发现或顺序$10^5 erg\, cm^{-2} s^{-1}$,与以前的DEMT和光谱研究一致。我们讨论了这些发现是如何与Alfvén波的日冕耗散相一致的。我们比较了不同的磁性结构的DEMT和AWSoM的三维结果。我们表明,这两种技术的产品之间的协议是迄今为止最好的,与整体协议$\lesssim 20\%$,取决于目标旋转和特定的冠状区域。然而,在其当前实现中,ASWsoM模型不能再现下行循环。此外,在太阳风的快速和慢速分量的源区,AWSoM模型的电子密度随纬度增加,与DEMT重建中观察到的趋势相反。

英文摘要:

We carry out a study of the global three-dimensional (3D) structure of the electron density and temperature of the quiescent inner solar corona ($r<1.25 R_\odot$) by means of tomographic reconstructions and magnetohydrodynamic simulations. We use differential emission measure tomography (DEMT) and the Alfvén Wave Solar Model (AWSoM), in their latest versions. Two target rotations were selected from the solar minimum between solar cycles (SCs) 23 and 24 and the declining phase of SC 24. We report in quantitative detail on the 3D thermodynamic structure of the core and outer layers of the streamer belt, and of the high latitude coronal holes (CH), as revealed by the DEMT analysis. We report on the presence of two types of structures within the streamer belt, loops with temperature decreasing/increasing with height (dubbed down/up loops), as reported first in previous DEMT studies. We also estimate the heating energy flux required at the coronal base to keep these structures stable, found to be or order $10^5 erg\, cm^{-2} s^{-1}$, consistently with previous DEMT and spectroscopic studies. We discuss how these findings are consistent with coronal dissipation of Alfvén waves. We compare the 3D results of DEMT and AWSoM in distinct magnetic structures. We show that the agreement between the products of both techniques is the best so far, with an overall agreement $\lesssim 20\%$, depending on the target rotation and the specific coronal region. In its current implementation the ASWsoM model can not reproduce down loops though. Also, in the source region of the fast and slow components of the solar wind, the electron density of the AWSoM model increases with latitude, opposite to the trend observed in DEMT reconstructions.

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。

↑