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

利用近红外色球吸收线直接测定恒星氦丰度

• 批准号: 21J11301
• 负责人: JIAN Mingjie
• 金额: $ 0.96万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2021
• 资助国家: 日本
• 起止时间: 2021-04-28 至 2023-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-21J11301/
• 关键词: stars: atmospheres; stars: chromospheres; stars: parameters; open clusters; globular clusters

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.

我们对10830 A处氦线的了解，即，He 10830是在现有研究的基础上进行改进的。我们收集了与He 10830形成相关的公共观测数据，以审查吸收强度与其他恒星参数之间的趋势。来自GIANO-B和HARPS的高分辨率光谱使我们能够校准He 10830周围混合线的污染情况。我们还建立了一种方法来测量强度的He 10830在一个高精度的拟合所有功能周围的波长。该方法适用于高分辨（>20000）和低分辨（~10000）谱。Teff、logR'HK和X射线光度比以前更清晰。基于Teff和logg可以约束主导形成机制。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。我们还观察到球状星团中的一些冷巨星，以证实这一结论，现在数据正在减少。我们还准备发表两篇关于我们结论的论文。恒星氦丰度仍然是研究星星和银河系演化的重要参数，值得进一步研究。

项目成果

Helium spectral lines at 10830A: observational trends with stellar parameters

10830A 处的氦谱线：恒星参数的观测趋势

• 发表时间: 2021
• 作者: Mingjie Jian;Noriyuki Matsunaga;Daisuke Taniguchi; Xiaoting Fu;Angela Bragaglia;Valentina D'Orazi;and WINERED team
• 通讯作者: and WINERED team