STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD
STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD
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DOI：
10.3847/0004-637x/818/1/31
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
P. Levens;B. Schmieder;N. Labrosse;A. L. Ariste
中科院分区：
文献类型：
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作者：
P. Levens;B. Schmieder;N. Labrosse;A. L. Ariste
我们研究了2014年7月15日观测到的“太阳龙卷风”的性质，旨在将等离子体的行为与相关日珥的内部磁场结构联系起来。我们使用SDO/AIA，界面区域成像光谱仪（IRIS）光谱仪和日之出/太阳光学望远镜（SOT）仪器进行了高空间分辨率和高节奏的多波长观测。沿着由Télescope Héliographique pour l 'Etude du Magnétisme et des Instabilités Solaires望远镜提供的分光偏振法，我们可以覆盖光学厚发射线和磁场信息。AIA揭示了日珥的两条腿是强烈吸收的结构，看起来像是在旋转，或者在天空平面上振荡。在Ca ii（SOT）中非常明亮的两条日珥腿，在IRIS Mg ii裂颚图像中看不到。这是解释了大的光学厚度的结构，在镁II，这导致反转的配置文件，因此在这些位置比在周围环境中的集成强度较低。使用在低于1 MK的温度下形成的谱线，我们在龙卷风状结构中测量到了±10 km s−1量级的相对较低的多普勒频移。在两条腿之间，我们看到Mg ii中的环，物质从一条腿流向另一条腿，以及逆流。很难将我们的数据解释为显示了两个与环无关的旋转垂直结构。这种“龙卷风”的情况与我们的观察不符。发现日珥两侧的磁场优先为水平磁场。
We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s−1 in the tornado-like structure. Between the two legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.