The Na i D resonance lines in main‐sequence late‐type stars
The Na i D resonance lines in main‐sequence late‐type stars
复制标题
主序晚型恒星中的 Na i D 共振线
DOI：
10.1111/j.1365-2966.2007.11833.x
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发表时间：
2007
影响因子：
4.8
通讯作者：
Argentina.
中科院分区：
文献类型：
--
作者：
R. D'iaz;C. Cincunegui;Pablo J. D. Mauas Instituto de Astronom'ia y F'isica del Aires;Argentina.
我们研究了晚型矮星的钠D谱线（D1: 5895.92 A; D2: 5889.95 A）。这些恒星的光谱类型在F6和M5.5之间（B−V在0.457和1.807之间），金属密度在(Fe/H) = - 0.82和0.6之间。我们利用位于阿根廷天文综合天文台（CASLEO）的2.15米望远镜获得了中等分辨率的梯队光谱。自1999年以来，这些观测定期进行。光谱在波长和通量上进行了校准。为我们所有的观测找到了伪连续统水平的定义。为了校准的目的，我们还定义了一个连续水平。我们详细计算了所有光谱的D线的等效宽度，并与恒星的色指数（B−V）有关。在可能的情况下，我们与以前的研究进行仔细的比较。最后，我们构造了一个光谱指数(R)作为D线通量与热通量之间的比值。我们发现，一旦校正了光球的贡献，该指数可以用作高活动水平恒星的色球活动指标。此外，我们发现结合我们的一些结果，我们获得了一种校准未知颜色的通量星的方法。
We study the sodium D lines (D1: 5895.92 A; D2: 5889.95 A) in late-type dwarf stars. The stars have spectral types between F6 and M5.5 (B − V between 0.457 and 1.807) and metal- licity between (Fe/H) =− 0.82 and 0.6. We obtained medium-resolution echelle spectra us- ing the 2.15-m telescope at the Argentinian observatory Complejo Astronomico El Leoncito (CASLEO). The observations have been performed periodically since 1999. The spectra were calibrated in wavelength and in flux. A definition of the pseudo-continuum level is found for all our observations. We also define a continuum level for calibration purposes. The equivalent width of the D lines is computed in detail for all our spectra and related to the colour index (B − V) of the stars. When possible, we perform a careful comparison with previous studies. Finally, we construct a spectral index (R � ) as the ratio between the flux in the D lines and the bolometric flux. We find that, once corrected for the photospheric contribution, this index can be used as a chromospheric activity indicator in stars with a high level of activity. Additionally, we find that combining some of our results, we obtain a method to calibrate in flux stars of unknown colour.