Chromospheric Activity of Periodic Variable Stars Based on the LAMOST Low- and Medium-resolution Spectral Survey
Chromospheric Activity of Periodic Variable Stars Based on the LAMOST Low- and Medium-resolution Spectral Survey
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DOI：
10.3847/1538-4365/abe30b
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发表时间：
2021-04
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影响因子：
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通讯作者：
L. Long;Li-yun Zhang;S. Bi;Jian-rong Shi;Hong-peng Lu;Xianming L. Han;Haifeng Wang;Misra Prabhakar
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作者：
L. Long;Li-yun Zhang;S. Bi;Jian-rong Shi;Hong-peng Lu;Xianming L. Han;Haifeng Wang;Misra Prabhakar
我们提出了一个目录的75,867周期变星的数据发布7的大天区多目标光纤光谱望远镜。我们计算了色球活动指数，201，349个光谱的等效宽度，以及130，796个光谱的超额分数光度（RHα′）。根据Hα线的强度，我们探测到30，719颗具有Hα填充或发射的F-、G-和K-型变星，以及2521颗具有Hα发射的M-型变星。此外，在30，573颗周期变星中，有14，938颗显示出Hα的变化。不同光谱类型的样本分析证实，后光谱类型的恒星的活动分数明显减少的绝对银河高度增加远离银道面。结果还表明，在相同的银河系绝对高度下，食双星的活动率比单星的活动率高。在这项研究中，我们提出了活动的旋转关系的F-，G-，K-和M-型变星。分析结果表明，在不饱和区，快速旋转星保持一个饱和值，幂律指数的绝对值从F型到K型星呈增大趋势。此外，我们还证实了角动量和磁动量之间存在正相关，这表明α-ω发电机可能是工作的。此外，我们还证实了Hα，Hβ，Hγ，Hδ，Ca ii H&K，Ca ii红外三重线之间的相关性。
We present a catalog of 75,867 periodic variable stars from data release 7 of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. We calculated the chromospheric activity index, equivalent widths for 201,349 spectra, and excess fractional luminosity ( RHα′ ) for 130,796 spectra. Based on the intensity of the Hα line, we detected 30,719 F-, G-, and K-type variable stars with Hα fill-in or emission and 2521 M-type variable stars exhibiting Hα emission. Furthermore, 14,938 out of 30,573 periodic variable stars showed Hα variability. Analysis of samples with different spectral types confirmed that the activity fraction of stars with later spectral type clearly decreases as the absolute Galactic height increases away from the Galactic plane. The results also show that at the same absolute Galactic height, the activity fractions in eclipsing binaries are higher than those in single stars. In this study, we present the activity–rotation relations for F-, G-, K-, and M-type variable stars. The results of analysis show that rapid rotators keep a saturated value, and the absolute value of the power-law index exhibits an increasing trend from F- to K-type stars in the unsaturated regime. Moreover, we confirm that the angular momentum and magnetic momentum are positively correlated, which indicates that the α–ω dynamo may be working. In addition, we confirmed the correlations among the Hα, Hβ, Hγ, Hδ, Ca ii H&K, and Ca ii infrared triplet lines.