A STATISTICAL STUDY OF TRANSVERSE OSCILLATIONS IN A QUIESCENT PROMINENCE
A STATISTICAL STUDY OF TRANSVERSE OSCILLATIONS IN A QUIESCENT PROMINENCE
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DOI：
10.1088/2041-8205/779/2/l16
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发表时间：
2013-10
期刊：
影响因子：
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通讯作者：
Andrew Hillier;Richard Morton;R. Erdélyi
中科院分区：
文献类型：
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作者：
Andrew Hillier;Richard Morton;R. Erdélyi
Hinode卫星的发射使人们能够以高分辨率和高节奏进行无视观测，使其非常适合于研究静止不动天体的动态。近年来，人们已经清楚地看到，静态共振支持小振幅的横向振荡，然而，样本量通常太小，无法得出一般性的结论。我们通过提供一个垂直日珥线横向振荡的统计研究来弥补这一点。在4小时的观测期间，可以测量3436个波的性质，发现周期从50到6000 s，典型的速度振幅在0.2到23 km s−1之间。大量的观测波允许确定的频率依赖性的波的属性和推导的速度功率谱的横波。对于小于7 mHz的频率，速度功率的频率依赖性是一致的速度功率谱产生的磁元素在光球的水平运动的观测，这表明日珥横波驱动的光球运动。然而，在更高的频率，这两个分布显着分歧，与相对更多的权力发现在更高的频率在日珥振荡。这些结果突出表明，在一个大的频率范围内的波是无处不在的连续性，并在较高的频率发现了大量的波能量。
The launch of the Hinode satellite has allowed for seeing-free observations at high-resolution and high-cadence making it well suited to study the dynamics of quiescent prominences. In recent years it has become clear that quiescent prominences support small-amplitude transverse oscillations, however, sample sizes are usually too small for general conclusions to be drawn. We remedy this by providing a statistical study of transverse oscillations in vertical prominence threads. Over a 4 hr period of observations it was possible to measure the properties of 3436 waves, finding periods from 50 to 6000 s with typical velocity amplitudes ranging between 0.2 and 23 km s−1. The large number of observed waves allows the determination of the frequency dependence of the wave properties and derivation of the velocity power spectrum for the transverse waves. For frequencies less than 7 mHz, the frequency dependence of the velocity power is consistent with the velocity power spectra generated from observations of the horizontal motions of magnetic elements in the photosphere, suggesting that the prominence transverse waves are driven by photospheric motions. However, at higher frequencies the two distributions significantly diverge, with relatively more power found at higher frequencies in the prominence oscillations. These results highlight that waves over a large frequency range are ubiquitous in prominences, and that a significant amount of the wave energy is found at higher frequency.