论文标题
欧米茄半人马座：红色巨人的MGH波段弱，直接追踪氦气含量
Omega Centauri: weak MgH-band in red giants directly trace the helium content
论文作者
论文摘要
分析了恒星参数和15个元素的化学丰度，包括通过线等效宽度或合成光谱分析，分析了恒星参数的高光谱分辨率和高光谱的光谱。对MGH和MG线的同时丰度分析，采用理论光谱以及HE/H $ - $比率的组合被证明是评估红色巨人比4400 K的氦气丰富度比4400 K的唯一强大的探针，否则否则，否则氦气线转移（He {\ scs I} 10830和5876Å），供某个分析范围，以供分析。与过去的研究一致，氦增强模型光电对产生的丰度比的影响小于0.15 DEX。本文在本文中针对最富含金属的簇成员测量的第一个间接光谱氦丰度揭示了七个He-hehanced巨人（$δ$$ y =+$ 0.15 $ \ pm 0.04 $ 0.04），这是迄今为止在光谱中发现的最大样本。 $ - $ 0.79 $ \ pm的平均金属性$ 0.06 dex和O，Na，al，Si，Ca，Ti，Ti，Ti，Ni，ba和La的丰度与Red Giant Branch（RGB-A）和Sub-Giant Branch（SGB-A）种群的价值一致，并建议Omega Centauri的人群中的Annauri samples sampelless samples samples samples samples samples samples samples samples samples。巨人的增强与较大的$ s $ process元素丰度相关，与al相关并与o造成反重。这些结果支持形成具有较大的欧米茄中心富含欧米茄的富含金属富含金属的欧米哥族群中的星体中培养基中的媒介中，与快速旋转的巨大星星的射流相同，既构成又有型号，又构成了Supernove and agiant groging and Suppernove and Suppernove and Suppernove drognove and Suppernov and Suppernove drognove and Suppernove（Supernove）。
High spectral resolution and high signal-to-noise ratio optical spectra of red giants in the globular cluster Omega Centauri are analysed for stellar parameters and chemical abundances of 15 elements including helium by either line equivalent widths or synthetic spectrum analyses. The simultaneous abundance analysis of MgH and Mg lines adopting theoretical photospheres and a combination of He/H$-$ratios proved to be the only powerful probe to evaluate helium abundances of red giants cooler than 4400 K, wherein otherwise helium line transitions (He {\scs I} 10830 and 5876 Å) present for a direct spectral line analysis. The impact of helium-enhanced model photospheres on the resulting abundance ratios are smaller than 0.15 dex, in agreement with past studies. The first indirect spectroscopic helium abundances measured in this paper for the most metal-rich cluster members reveal the discovery of seven He-enhanced giants ($Δ$$Y=+$0.15$\pm$0.04), the largest such sample found spectroscopically to date. The average metallicity of $-$0.79$\pm$0.06 dex and abundances for O, Na, Al, Si, Ca, Ti, Ni, Ba, and La are consistent with values found for the red giant branch (RGB-a) and subgiant branch (SGB-a) populations of Omega Centauri, suggesting an evolutionary connection among samples. The He-enhancement in giants is associated with larger $s$-process elemental abundances, which correlate with Al and anticorrelate with O. These results support the formation of He-enhanced, metal-rich population of Omega Centauri out of the interstellar medium enriched with the ejecta of fast rotating massive stars, binaries exploding as supernovae and asymptotic giant branch (AGB) stars.
