Stereoscopy of extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI
Stereoscopy of extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI
复制标题
太阳轨道飞行器/EUI 观测到的极端紫外线安静太阳增亮的立体观测
DOI：
10.1051/0004-6361/202141010
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发表时间：
2021
影响因子：
6.5
通讯作者：
D. Berghmans
中科院分区：
文献类型：
--
作者：
A. Zhukov;M. Mierla;F. Auchère;S. Gissot;L. Rodriguez;E. Soubri'e;W. Thompson;B. Inhester;B. Nicula;P. Antolin;S. Parenti;'Eric Buchlin;Krzysztof Barczynski;C. Verbeeck;E. Kraaikamp;P. Smith;K. Stegen;L. Dolla;L. Harra;D. Long;U. Schuhle;O. Podladchikova;R. A. Cuadrado;L. Teriaca;M. Haberreiter;A. Katsiyannis;P. Rochus;J. Halain;L. Jacques;D. Berghmans
太阳大气的三维精细结构仍然不能完全理解，因为大多数可用的观测都是从一个有利位置进行的。本文的目的是研究由太阳轨道飞行器上的极紫外成像仪（EUI）在EUV安静太阳中发现的小尺度增亮事件（“营火”）的三维分布。我们使用了EUI的高分辨率EUV望远镜于2020年5月30日在174 {\AA}波段获得的第一个调试数据集，并将其与太阳动力学天文台上的大气成像组件（AIA）在类似的171 {\AA}波段获得的同步数据相结合。两个望远镜的两像素空间分辨率分别为400公里和880公里，这足以识别两个数据集中的营火。这两个航天器的角度分离约为31.5度（基本上是在日冕经度上），这允许对营火位置进行3D重建。这些观测首次在如此小的尺度上实现了立体增亮。使用手动和自动三角测量方法对营火数据进行表征。营火的高度位于光球上方1000公里至5000公里之间，我们发现手动和自动方法之间的一致性很好。营火的内部结构大多未被AIA解决；然而，对于一个特别大的营火，我们能够对几个像素进行三角测量，这些像素都在2500到4500公里的狭窄范围内。EUI营火的低高度表明它们属于以前未解决的过渡区精细结构和安静太阳的低日冕。它们可能是内部加热到日冕温度的小规模动态循环的顶点。这项工作表明，太阳大气结构的高分辨率立体观测已经成为可能。
The 3D fine structure of the solar atmosphere is still not fully understood as most of the available observations are taken from a single vantage point. The goal of the paper is to study the 3D distribution of small-scale brightening events ("campfires") discovered in the EUV quiet Sun by the Extreme Ultraviolet Imager (EUI) aboard Solar Orbiter. We used a first commissioning data set acquired by the EUI's High Resolution EUV telescope on 30 May 2020 in the 174 {\AA} passband and we combined it with simultaneous data taken by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory in a similar 171 {\AA} passband. The two-pixel spatial resolution of the two telescopes is 400 km and 880 km, respectively, which is sufficient to identify the campfires in both data sets. The two spacecraft had an angular separation of around 31.5 degrees (essentially in heliographic longitude), which allowed for the 3D reconstruction of the campfire position. These observations represent the first time that stereoscopy was achieved for brightenings at such a small scale. Manual and automatic triangulation methods were used to characterize the campfire data. The height of the campfires is located between 1000 km and 5000 km above the photosphere and we find a good agreement between the manual and automatic methods. The internal structure of campfires is mostly unresolved by AIA; however, for a particularly large campfire, we were able to triangulate a few pixels, which are all in a narrow range between 2500 and 4500 km. The low height of EUI campfires suggests that they belong to the previously unresolved fine structure of the transition region and low corona of the quiet Sun. They are probably apexes of small-scale dynamic loops heated internally to coronal temperatures. This work demonstrates that high-resolution stereoscopy of structures in the solar atmosphere has become feasible.