Tracking magnetic bright point motions through the solar atmosphere
Tracking magnetic bright point motions through the solar atmosphere
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DOI：
10.1093/mnras/sts268
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发表时间：
2012-10
影响因子：
4.8
通讯作者：
P. Keys;M. Mathioudakis;D. Jess;S. Shelyag;D. Christian;F. Keenan
中科院分区：
文献类型：
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作者：
P. Keys;M. Mathioudakis;D. Jess;S. Shelyag;D. Christian;F. Keenan
采用高频差、多波长观测和模拟方法，对宁静太阳光球磁亮点进行了分析。这些观测是由邓恩太阳望远镜的太阳大气层快速振荡成像仪和干涉二维光谱仪获得的。我们的分析显示，光球的MBP平均横向速度约为1 km s-1，而色球的MBP平均速度略高，为1.4 km s-1。此外，发现色球的最大平均压比相当的光球最大平均压大63%左右。将这些速度值与使用MURAM代码生成的数值模拟的输出进行比较。模拟结果相似，但与观测数据相比略有升高。在模拟的G波段图像中发现平均速度为1.3 km s-1，在连续体形成层上方500 km高度的速度域中发现平均速度为1.8 km s-1。还分析了速度变化的延迟。建立了模拟数据集各层之间的平均延迟为104 s，在G波段和Ca II K ROSA观测之间观察到1029 s的值。模拟中的延迟很可能是斜颗粒激波的结果，而观测中发现的延迟可能是半刚性通量管的结果。
High-cadence, multiwavelength observations and simulations are employed for the analysis of solar photospheric magnetic bright points (MBPs) in the quiet Sun. The observations were obtained with the Rapid Oscillations in the Solar Atmosphere (ROSA) imager and the Interferometric Bidimensional Spectrometer at the Dunn Solar Telescope. Our analysis reveals that photospheric MBPs have an average transverse velocity of approximately 1 km s−1, whereas their chromospheric counterparts have a slightly higher average velocity of 1.4 km s−1. Additionally, chromospheric MBPs were found to be around 63 per cent larger than the equivalent photospheric MBPs. These velocity values were compared with the output of numerical simulations generated using the MURAM code. The simulated results were similar, but slightly elevated, when compared to the observed data. An average velocity of 1.3 km s−1 was found in the simulated G-band images and an average of 1.8 km s−1 seen in the velocity domain at a height of 500 km above the continuum formation layer. Delays in the change of velocities were also analysed. Average delays of ∼4 s between layers of the simulated data set were established and values of ∼29 s observed between G-band and Ca II K ROSA observations. The delays in the simulations are likely to be the result of oblique granular shock waves, whereas those found in the observations are possibly the result of a semi-rigid flux tube.