标题： 太阳轨道器/极紫外成像仪观测到的扇脊拓扑结构：旋转运动和阿尔芬波的迹象 显示英文标题

标题： Observations of Fan-Spine Topology by Solar Orbiter/EUI: Rotational Motions and Indications of Alfvén Waves

摘要： 扭转阿尔芬波不会产生任何强度变化，因此用成像仪器观测极具挑战性。此前，通过光谱成像，在太阳大气的所有层次都报告了阿尔芬波的观测结果。我们展示了通过Solar Orbiter卫星上的EUI仪器的HRIEUV望远镜在174 Å通道中观测到的一个扭转阿尔芬波，该波出现在一个倒Y形结构中。这一特征由两个足点通过短环和一个长度为30 Mm的脊连接组成，该脊起源于其中一个足点。在当前工作中，我们还利用了Solar Orbiter卫星上另外两种仪器的同时观测数据。第一种是PHI，用于推导所观测特征的磁场配置。第二种是SPICE，提供了不同线（包括Ne VIII和C III线）的强度图观测。我们还通过前向建模分析讨论了SPICE点扩散函数及其对多普勒图的影响问题。差异电影显示脊部存在明显的传播旋转运动迹象。使用SPICE获得的多普勒图在脊部区域显示出强烈的信号。假设恢复的点扩散函数基本正确，合成的扫描图像确认该信号主要是物理性的。我们得出结论，这些观测结果与低日冕结构中的传播扭转阿尔芬波或磁通绳解缠绕的解释相兼容。这是第一次我们看到Solar Orbiter卫星上的三种仪器观测到的日冕中传播扭转运动的特征。 显示英文摘要

摘要： Torsional Alfv\'en waves do not produce any intensity variation and are, therefore, challenging to observe with imaging instruments. Previously, Alfv\'en wave observations were reported throughout all the layers of the solar atmosphere using spectral imaging. We present an observation of a torsional Alfv\'en wave detected in an inverted y-shape structure observed with the HRIEUV telescope of the EUI instrument onboard Solar Orbiter in its 174 \r{A} channel. The feature consists of two footpoints connected through short loops and a spine with a length of 30 Mm originating from one of the footpoints. In the current work, we also make use of the simultaneous observations from two other instruments onboard Solar Orbiter. The first one is PHI that is used to derive the magnetic configuration of the observed feature. The second one is SPICE that provided observations of intensity maps in different lines including Ne VIII and C III lines. We also address the issues of the SPICE point spread function and its influence on the Doppler maps via performed forward modeling analysis. The difference movie shows clear signatures of propagating rotational motions in the spine. Doppler maps obtained with SPICE show strong signal in the spine region. Under the assumption that the recovered point spread function is mostly correct, synthesized raster images confirm that this signal is predominantly physical. We conclude that the presented observations are compatible with an interpretation of either propagating torsional Alfv\'en waves in a low coronal structure or untwisting of a flux rope. This is the first time we see signatures of propagating torsional motion in corona as observed by the three instruments onboard Solar Orbiter.