arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1205.0891astro-ph.SR
收藏

日冕环中的扰动传播速度的详细分析

Propagating Disturbances in Coronal Loops: A Detailed Analysis of Propagation Speeds

G. Kiddie, I. De Moortel, G. Del Zanna, S. W. McIntosh, I. Whittaker

摘要:

多年来,人们一直在太阳大气层外观测到准周期扰动。虽然最初被解释为上升流(Schrijver等人(1999)),但由于观察到的速度和周期,它们已被广泛认为是慢磁声波。然而,最近的观测对这种解释提出了质疑,因为发现多普勒速度、线宽和轮廓不对称性的周期性扰动与强度振荡同相(De Pontieu等人(2010),Tian1等人(2011)),这表明扰动可能是准周期性的上升流。在这里,我们进行了详细的分析,这些扰动的速度在几个波长使用的大气成像组件(AIA)板上的太阳动力学天文台(SDO)。我们分析了41个例子,包括太阳黑子和非太阳黑子区域。我们发现,位于太阳黑子的传播扰动(PD)的速度更可能是温度依赖性,而在非太阳黑子位置的PD的速度没有表现出明确的温度依赖性。我们还考虑了潜在驱动因素对PD属性的影响程度。最后,我们发现,去除193 A波长中较冷离子的贡献表明,太阳黑子PD的193发射的相当大一部分可以贡献给193 A的冷分量。

英文摘要:

Quasi-periodic disturbances have been observed in the outer solar atmosphere for many years now. Although first interpreted as upflows (Schrijver et al. (1999)), they have been widely regarded as slow magnetoacoustic waves, due to observed velocities and periods. However, recent observations have questioned this interpretation, as periodic disturbances in Doppler velocity, line width and profile asymmetry were found to be in phase with the intensity oscillations (De Pontieu et al. (2010),Tian1 et al. (2011))}, suggesting the disturbances could be quasi-periodic upflows. Here we conduct a detailed analysis of the velocities of these disturbances across several wavelengths using the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). We analysed 41 examples, including both sunspot and non sunspot regions of the Sun. We found that the velocities of propagating disturbances (PDs) located at sunspots are more likely to be temperature dependent, whereas the velocities of PDs at non sunspot locations do not show a clear temperature dependence. We also considered on what scale the underlying driver is affecting the properties of the PDs. Finally, we found that removing the contribution due to the cooler ions in the 193 A wavelength suggests that a substantial part of the 193 emission of sunspot PDs can be contributed to the cool component of 193Å.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑