Temperature and Density Structure of a Recurring Active Region Jet
Temperature and Density Structure of a Recurring Active Region Jet
复制标题
DOI：
10.1051/0004-6361/201628796
复制
发表时间：
2016-09
期刊：
影响因子：
--
通讯作者：
Sargam M. Mulay;G. Zanna;H. Mason
中科院分区：
文献类型：
--
作者：
Sargam M. Mulay;G. Zanna;H. Mason
我们介绍了2011年10月31日由SDO/AIA、Hinode/XRT和Hinode/EIS观测到的一次重现急流的研究。我们讨论了用成像和光谱观测得到的射流的物理参数，如密度、差分发射测量、峰值温度、速度和填充因子。利用EIS观测以及AIA和XRT观测相结合的方法，对喷流尖顶和脚点区域进行了差示发射测量(DEM)分析。DEM曲线被用来与基安蒂红酒原子数据库创建合成光谱。喷流尖顶和喷脚点视线方向的等离子体在2.0mK处达到峰值。我们使用FeXII($\lambda$186/$\lambda$195)线比计算了尖顶区域(ne=7.6x$10^{10}$$cm^-3}$)和足点(1.1x$10^{11}$$cm^-3}$)的电子密度。测得喷流的天面速度为524公里/S，计算得到的EISDEM值与AIA-XRT的结果吻合较好。没有高温的迹象，例如喷气尖顶中看到的FeXvii($\lambda$254.87)(log T[K]=6.75)的排放。在喷流足迹的情况下，合成光谱预测了CaXvii($\lambda$192.85)和Fe Xvii($\lambda$254.87)的微弱贡献。通过进一步的调查，我们证实了足点区域AIA94$Aa通道中的FeXVIII($\lambda$93.932)线的发射。我们还发现，估计的Fe XVIII计数率和预测的Fe XVIII计数率之间有很好的一致性。对喷流足点的时间演化和FeXVIII(logT[K]=6.85)谱线的高温发射的研究表明，喷流足点中的热成分最初存在，当EIS观测到它时，喷流已经冷却。
We present a study of a recurring jet observed on October 31, 2011 by SDO/AIA, Hinode/XRT and Hinode/EIS. We discuss the physical parameters of the jet such as density, differential emission measure, peak temperature, velocity and filling factor obtained using imaging and spectroscopic observations. A differential emission measure (DEM) analysis was performed at the region of the jet-spire and the footpoint using EIS observations and also by combining AIA and XRT observations. The DEM curves were used to create synthetic spectra with the CHIANTI atomic database. The plasma along the line-of-sight in the jet-spire and jet-footpoint was found to be peak at 2.0 MK. We calculated electron densities using the Fe XII ($\lambda$186/$\lambda$195) line ratio in the region of the spire (Ne = 7.6x$10^{10}$ $cm^{-3}$) and the footpoint (1.1x$10^{11}$ $cm^{-3}$). The plane-of-sky velocity of the jet is found to be 524 km/s. The resulting EIS DEM values are in good agreement with those obtained from AIA-XRT. There is no indication of high temperatures, such as emission from Fe XVII ($\lambda$254.87) (log T [K] = 6.75) seen in the jet-spire. In case of the jet-footpoint, synthetic spectra predict weak contributions from Ca XVII ($\lambda$192.85) and Fe XVII ($\lambda$254.87). With further investigation, we confirmed emission from the Fe XVIII ($\lambda$93.932) line in the AIA 94 ${\AA}$ channel in the region of the footpoint. We also found good agreement between the estimated and predicted Fe XVIII count rates. A study of the temporal evolution of the jet-footpoint and the presence of high-temperature emission from the Fe XVIII (log T [K] = 6.85) line leads us to conclude that the hot component in the jet-footpoint was present initially that the jet had cooled down by the time EIS observed it.