Direct determination of stellar helium abundance using near-infrared chromospheric absorption line

在目前研究的基础上，我们对10830A氦谱线，即He10830谱线的认识得到了改进。我们收集了与He10830形成相关的公开观测数据，以回顾吸收强度与其他恒星参数之间的趋势。Giano-B和HARPS的高分辨率光谱使我们能够校准He10830周围混合生产线的污染情况。我们还建立了一种通过对He10830波长周围的所有特征进行拟合来高精度测量He10830强度的方法。这种方法对高分辨率(~gt；20000)和低分辨率(~10000)谱都适用，而且比以前更清楚地反映了He10830的一些强度变化趋势，如Teff值、对数和X射线光度。主导的形成机制可以根据Teff值和Logg来约束。冷巨星的强度预计会对氦丰度表现出一定的敏感性，而其他恒星的强度则不会。我们还观察了球状星系团中的几个冷巨星来证实这一结论，现在数据正在减少。我们还准备很快发表两篇关于我们结论的论文。恒星氦丰度仍然是恒星和银河系演化的重要参数，值得进一步研究。

Our knowledge on the helium line at 10830A, i.e., He10830, is now improved based on the current research. We gathered the public observation data relevant to the formation of He10830 to review the trend between the absorption strength and other stellar parameters. The high-resolution spectra from GIANO-B and HARPS allow us to calibrate the contamination situation of blending lines around He10830. We also establish a method for measuring the strength of He10830 in a high precision by fitting all the features around that wavelength. This method is found to be applicable for both high resolution (>20000) and low resolution (~10000) spectra.Some trends of the strength of He10830 with, e.g., Teff, logR'HK and X-ray luminosity are more clear then before. The dominant formation mechanism can be constrained based on the Teff and logg. The strength of cool giants are expected to show some sensitivity with helium abundance, while that of other stars are not. We also observed a few cool giants in the globular cluster to conform this conclusion, and now the data are being reduced. We are also preparing to publish two papers about our conclusion soon. The stellar helium abundance is still an essential parameter for both the evolution of star and milky way, and it is worth further research.