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arXiv 1407.7124astro-ph.SR
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用Hinode/EUV成像光谱仪(EIS)观测日冕漏斗中热脉冲驱动的等离子体流

On Thermal-Pulse-Driven Plasma Flows in Coronal Funnels as Observed by Hinode/EUV Imaging Spectrometer (EIS)

A. K. Srivastava, P. Konkol, K. Murawski, B. N. Dwivedi, A. Mohan

摘要:

2007年2月5日,利用日出/极紫外成像光谱仪(EIS)的单弧秒狭缝扫描观测,我们发现在AR 10940东边界的开放和扩张的日冕漏斗中存在等离子体流出。Fe XII 195.120 A的多普勒速度图表明,弥散闭环系统大部分红移。在AR东部边界的开放拱门(漏斗)显示蓝移,最大速度约为10-15 km/s。这意味着通过这些磁性结构流出等离子体。为了支持这些观测结果,我们使用FLASH代码在适当的VAL-III C初始温度条件下通过求解一组理想MHD方程来进行扩展日冕漏斗的二维数值模拟。我们实现了一个稀薄的和更热的区域在模型漏斗的足点,这导致在缓慢的等离子体扰动的等离子体流的形式向外传播的演变。我们的结论是,加热,这可能是由于磁重联,可以触发所观察到的等离子体外流在这样的日冕漏斗。这可以将质量输送到更高的日冕中,从而形成新生的太阳风。

英文摘要:

Using one-arcsecond-slit scan observations from the Hinode/EUV Imaging Spectrometer (EIS) on 05 February 2007, we find the plasma outflows in the open and expanding coronal funnels at the eastern boundary of AR 10940. The Doppler velocity map of Fe XII 195.120 A shows that the diffuse close-loop system to be mostly red-shifted. The open arches (funnels) at the eastern boundary of AR exhibit blue-shifts with a maximum speed of about 10-15 km/s. This implies outflowing plasma through these magnetic structures. In support of these observations, we perform a 2D numerical simulation of the expanding coronal funnels by solving the set of ideal MHD equations in appropriate VAL-III C initial temperature conditions using the FLASH code. We implement a rarefied and hotter region at the footpoint of the model funnel, which results in the evolution of slow plasma perturbations propagating outward in the form of plasma flows. We conclude that the heating, which may result from magnetic reconnection, can trigger the observed plasma outflows in such coronal funnels. This can transport mass into the higher corona, giving rise to the formation of the nascent solar wind.

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