A Study of Polar Jet Parameters Based on Hinode XRT Observations
A Study of Polar Jet Parameters Based on Hinode XRT Observations
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DOI：
10.1093/pasj/59.sp3.s771
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发表时间：
2007-11
影响因子：
2.3
通讯作者：
A. Savcheva;J. Cirtain;E. DeLuca;L. Lundquist;L. Golub;M. Weber;M. Shimojo;K. Shibasaki;T. Sakao;N. Narukage;S. Tsuneta;R. Kano
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文献类型：
--
作者：
A. Savcheva;J. Cirtain;E. DeLuca;L. Lundquist;L. Golub;M. Weber;M. Shimojo;K. Shibasaki;T. Sakao;N. Narukage;S. Tsuneta;R. Kano
Hinode/SOHO Campaign 7197是迄今为止在南北极冕洞内对极地喷流形成和演化进行的最广泛的研究。这项研究首次表明，在日冕洞中出现X射线喷流的频率非常高--平均约为60个喷流d1。利用X光望远镜在Hinode上收集的观测数据，对大量喷流样本的一些物理参数进行了统计研究。我们测量了射流的表观向外速度、高度、宽度和寿命。在我们的样本中，所有这些参数都表现出峰值分布，其中向外速度的最大值为160 km S 1，高度为5 10公里，宽度为8 10公里，喷流寿命约为10分钟。我们还首次对喷流横向运动进行了统计研究，得到了S 0-35公里的横向速度。这些数值是在一个更大的(就频率而言)和更好的抽样事件集合的基础上获得的，而不是之前的统计研究(Shimojo等人)。1996年，PASJ，48,123)。XRT的独特特性使这一结果成为可能。我们描述了用于确定特征和设定一些未来目标的方法。我们还表明，尽管存在一些可能的选择效应，但喷流最好发生在极地冕洞内。
Hinode/SOHO campaign 7197 is the most extensive study of polar jet formation and evolution from within both the north and south polar coronal holes so far. For the first time, this study showed that the appearance of X-ray jets in the solar coronal holes occurs at very high frequency — about 60 jets d 1 on average. Using observations collected by the X-Ray Telescope on Hinode, a number of physical parameters from a large sample of jets were statistically studied. We measured the apparent outward velocity, the height, the width and the lifetime of the jets. In our sample, all of these parameters show peaked distributions with maxima at 160 km s 1 for the outward velocity, 5 10 km for the height, 8 10 km for the width, and about 10 min for the lifetime of the jets. We also present the first statistical study of jet transverse motions, which obtained transverse velocities of 0–35 km s . These values were obtained on the basis of a larger (in terms of frequency) and better sampled set of events than what was previously statistically studied (Shimojo et al. 1996, PASJ, 48, 123). The results were made possible by the unique characteristics of XRT. We describe the methods used to determine the characteristics and set some future goals. We also show that despite some possible selection effects, jets preferably occur inside the polar coronal holes.