arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1502.07068astro-ph.SR
收藏

由Hinode上的EUV成像光谱仪测量的活动区流出的电子密度

Electron density of active region outflows measured by the EUV Imaging Spectrometer onboard Hinode

Naomasa Kitagawa, Takaaki Yokoyama

摘要:

为了更好地了解活动区外流的性质,利用密度敏感的Fe xiv 264.78A/274.20A线对测量了活动区外流的电子密度,由于外流区的日冕线轮廓由多普勒频移< 10 km s^-1的主分量和次分量组成,(增强型蓝翼:EBW)蓝移高达100 km/s,我们通过双高斯拟合从谱线轮廓中提取EBW。我们尝试将同时拟合应用于具有几个物理限制的这两条Fe xiv线。根据CHIANTI数据库,通过参考作为电子密度函数的理论强度比,计算两种组分的电子密度(分别为n_Major和n_EBW)。我们研究了NOAA AR 10978周围流出区域的六个位置。平均电子密度为n_Major = 10^(9.16 +- 0.16)cm^-3,n_EBW = 10^(8.74 +- 0.29)cm^-3。在东、西部外流区,n_Major与n_EBW的大小关系相反。还计算了每个分量的柱深,这导致流出在东部地区仅占一小部分(~ 0.1),而在西部地区,流出在线剖面中占主导地位的主要分量为5倍。当考虑到扩展的日冕结构时,西部区域可以被认为代表了质量泄漏。相反,我们提出了一种可能性,即东部地区实际上有助于日冕环的质量供应。

英文摘要:

In order to better understand the nature of active region outflows, the electron density was measured by using a density-sensitive line pair Fe xiv 264.78A/274.20A.Since coronal line profiles of the outflow region are composed of a major component with a Doppler shift of < 10 km s^-1 and a minor component (enhanced blue wing: EBW) blueshifted by up to 100 km s^-1, we extracted EBW from the line profiles through double-Gaussian fitting. We tried applying the simultaneous fitting to those two Fe xiv lines with several physical restrictions. Electron density for both components (n_Major and n_EBW, respectively) was calculated by referring to the theoretical intensity ratio as a function of electron density as per the CHIANTI database. We studied six locations in the outflow regions around NOAA AR10978. The average electron density was n_Major = 10^(9.16 +- 0.16) cm^-3 and n_EBW = 10^(8.74 +- 0.29) cm^-3. The magnitude relationship between n_Major and n_EBW was opposite in the eastern and western outflow regions. The column depth was also calculated for each component, which leads to the result that the outflows possess only a small fraction (~ 0.1) in the eastern region, while they dominate over the major component in the line profiles by a factor of five in the western region. When taking into account the extending coronal structures, the western region can be thought to represent the mass leakage. In contrast, we suggest a possibility that the eastern region actually contributes to the mass supply to coronal loops.

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。

↑