REDSHIFTS, WIDTHS, AND RADIANCES OF SPECTRAL LINES EMITTED BY THE SOLAR TRANSITION REGION
REDSHIFTS, WIDTHS, AND RADIANCES OF SPECTRAL LINES EMITTED BY THE SOLAR TRANSITION REGION
复制标题
太阳过渡区域发出的光谱线的红移、宽度和辐射度
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
G. Doschek
中科院分区：
文献类型：
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作者：
U. Feldman;I. Dammasch;G. Doschek
理解过渡区物理的一个长期问题是过渡区紫外谱线相对于色球发射线的普遍红移，这一结果从天空实验室时代就知道了。太阳和日光层天文台发射辐射光谱仪的太阳紫外线测量系统对太阳圆盘不同区域进行的扩展光谱扫描，每项研究包含数千条谱线轮廓，从而能够彻底调查红移现象。在使用这些从色球到日冕温度范围的线构成的七个不同圆盘区域的数据时，我们推导出了多普勒波长移动与辐射之间的关系以及线宽与辐射之间的关系。虽然由非常明亮的等离子体发出的色球和日冕线在某些情况下可能会显示出明显的红移，但过渡区的线主要在平静的太阳和活动区的任何地方都显示出红移。然而，在冕洞中，它们表现出减少的移位，有时完全消失。将描述观察结果和调查结果，并考虑可能的解释。
A long-standing problem in understanding the physics of the transition region has been the ubiquitous redshifts of transition region ultraviolet spectral lines relative to chromospheric emission lines, a result known since the Skylab era. Extended spectral scans performed for various regions of the solar disk by the Solar Ultraviolet Measurements of Emitted Radiation spectrometer on the Solar and Heliospheric Observatory contain thousands of line profiles per study and allow a thorough investigation of the redshift phenomenon. In using these data from seven distinct disk areas made in lines spanning the chromosphere to coronal temperature range, we derive a relationship between Doppler wavelength shifts and radiances and a relationship between line widths and radiances. While chromospheric and coronal lines emitted by very bright plasmas may in some cases show pronounced redshifts, transition-region lines predominantly show redshifts everywhere in the quiet Sun and in active regions. In coronal holes, however, they display a reduced shift, which at times altogether disappears. The observations and the findings will be described, and possible explanations will be considered.