arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1002.1197astro-ph.SR
收藏

静止双折射中的SUMER莱曼α谱线

The SUMER Lyman-alpha line profile in quiescent prominences

W. Curdt, H. Tian, L. Teriaca, U. Schühle

摘要:

目的:在一个新的观测技术,我们发表的第一次,SoHO-SUMER观测到的真正的谱线轮廓的氢莱曼-α在静态双折射。由于SoHO不在地球轨道上,我们的高质量数据集不受地冠吸收的影响。我们研究了线的轮廓,并将其与早期观测的高莱曼线和最近的模型预测。研究方法:我们应用缩减孔径观测模式对两个日珥目标进行观测,并对两个数据集中的谱线轮廓进行了统计分析。特别是,我们研究了轮廓的形状,辐射率分布和线形状与辐射率的相互关系。我们还比较了Ly-a数据的同时1206硅III数据。结果如下:我们发现,Ly-a的平均配置文件有一个蓝峰的优势,是更逆转,如果视线是垂直于磁力线。Ly-a日珥辐射光栅的对比度很低,其辐射亮度分布与星盘的对数正态分布不同。在Si III线中看到的特征并不总是与Ly-a发射共空间。结论:我们的实证结果支持最近的多线程模型,它预测的不对称性和深度的自反转依赖于日珥轴相对于视线的方向。

英文摘要:

Aims: Out of a novel observing technique, we publish for the first time, SoHO-SUMER observations of the true spectral line profile of hydrogen Lyman-alpha in quiescent prominences. With SoHO not being in Earth orbit, our high-quality data set is free from geocoronal absorption. We study the line profile and compare it with earlier observations of the higher Lyman lines and recent model predictions. Methods: We applied the reduced-aperture observing mode to two prominence targets and started a statistical analysis of the line profiles in both data sets. In particular, we investigated the shape of the profile, the radiance distribution and the line shape-to-radiance interrelation. We also compare Ly-a data to co-temporal 1206 Si III data. Results: We find that the average profile of Ly-a has a blue-peak dominance and is more reversed, if the line-of-sight is perpendicular to the field lines. The contrast of Ly-a prominence emission rasters is very low and the radiance distribution differs from the log-normal distribution of the disk. Features seen in the Si III line are not always co-spatial with Ly-a emission. Conclusions: Our empirical results support recent multi-thread models, which predict that asymmetries and depths of the self-reversal depend on the orientation of the prominence axis relative to the line-of-sight.

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。

↑