论文标题

使用T分布的随机邻居嵌入高分辨率太阳Hα光谱的分类

Classification of High-resolution Solar Hα Spectra using t-distributed Stochastic Neighbor Embedding

论文作者

Verma, Meetu, Matijevič, Gal, Denker, Carsten, Diercke, Andrea, Dineva, Ekaterina, Balthasar, Horst, Kamlah, Robert, Kontogiannis, Ioannis, Kuckein, Christoph, Pal, Partha S.

论文摘要

Hα光谱线是一条良好的吸收系,揭示了高度结构化和动态太阳能球层的特性。 Hα中具有独特光谱特征的典型特征包括细丝和突出,明亮的活动区域,围绕黑子,涌动,耀斑,Ellerman炸弹,花丝以及莫特尔斯和玫瑰花塞等的超肾上腺。这项研究基于位于西班牙特内里费岛的Observatorio del Teide(ODT)的真空塔望远镜(VTT)获得的高光谱分辨率Hα光谱。 T分布的随机邻居嵌入(T-SNE)是一种机器学习算法,用于非线性维度降低。在此应用中,它将Hα光谱投射到二维图上,在该图中可以根据云模型(CM)反转的结果对光谱进行分类。 CM参数光学深度,多普勒宽度,视线速度和源函数描述了云材料的属性。 T-SNE的初始结果表明其强大的歧视能力可以将安静的sim和绘制曲线与适合CM反转的歧义分开。此外,进行了各种T-SNE参数的详细研究,评估了条件对分类的影响,比较各种输入数据的结果,并且已确定的簇与色球层特征有关。尽管T-SNE被证明在聚类高维数据方面是有效的,但在每个步骤中都需要人类推断来解释结果。这项探索性研究提供了一个关于如何针对特定光谱数据和科学问题定制分类方案的框架和想法。

The Hα spectral line is a well-studied absorption line revealing properties of the highly structured and dynamic solar chromosphere. Typical features with distinct spectral signatures in Hα include filaments and prominences, bright active-region plages, superpenumbrae around sunspots, surges, flares, Ellerman bombs, filigree, and mottles and rosettes, among others. This study is based on high-spectral resolution Hα spectra obtained with the echelle spectrograph of the Vacuum Tower Telescope (VTT) located at Observatorio del Teide (ODT), Tenerife, Spain. The t-distributed Stochastic Neighbor Embedding (t-SNE) is a machine learning algorithm, which is used for nonlinear dimensionality reduction. In this application, it projects Hα spectra onto a two-dimensional map, where it becomes possible to classify the spectra according to results of Cloud Model (CM) inversions. The CM parameters optical depth, Doppler width, line-of-sight velocity, and source function describe properties of the cloud material. Initial results of t-SNE indicate its strong discriminatory power to separate quiet-Sun and plage profiles from those that are suitable for CM inversions. In addition, a detailed study of various t-SNE parameters is conducted, the impact of seeing conditions on the classification is assessed, results for various types of input data are compared, and the identified clusters are linked to chromospheric features. Although t-SNE proves to be efficient in clustering high-dimensional data, human inference is required at each step to interpret the results. This exploratory study provides a framework and ideas on how to tailor a classification scheme towards specific spectral data and science questions.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源