论文标题
三分钟振荡的源深度
Source Depth of Three-minute Umbral Oscillations
论文作者
论文摘要
我们推断出内部来源的深度，导致三分钟的umbral振荡。最近观察到翁布拉尔振荡的波纹状速度模式的观察结果支持了以下观点：存在内部来源令人兴奋。我们采用这样的假设，即在光谱层下方的源沿不同路径传播，在不同时间到达表面并通过模式转换激发慢的MHD波。这些缓慢的MHD波被视为显然可以水平传播的涟漪。给定作为时间函数的波纹的传播距离与源深度密切相关。使用Big Bear Solar天文台的Goode太阳能望远镜的快速成像太阳能光谱仪采集的Fe I 5435A线的光谱数据，我们确定了五个涟漪，并确定了每个纹波中时间的繁殖距离作为时间的函数。从模型拟合到这些数据，我们获得了1000公里至2000 km之间的深度。我们的结果将是理解黑子中磁反射和波产生的详细过程的观察性约束。
We infer the depth of the internal sources giving rise to three-minute umbral oscillations. Recent observations of ripple-like velocity patterns of umbral oscillations supported the notion that there exist internal sources exciting the umbral oscillations. We adopt the hypothesis that the fast magnetohydrodynamic (MHD) waves generated at a source below the photospheric layer propagate along different paths, reach the surface at different times, and excited slow MHD waves by mode conversion. These slow MHD waves are observed as the ripples that apparently propagate horizontally. The propagation distance of the ripple given as a function of time is strongly related to the depth of the source. Using the spectral data of the Fe I 5435A line taken by the Fast Imaging Solar Spectrograph of the Goode Solar Telescope at Big Bear Solar Observatory, we identified five ripples and determined the propagation distance as a function of time in each ripple. From the model fitting to these data, we obtained the depth between 1000 km and 2000 km. Our result will serve as an observational constraint to understanding the detailed processes of magnetoconvection and wave generation in sunspots.
