论文标题
使用氟在两个CEMP祖细胞中约束核合成
Constraining Nucleosynthesis in Two CEMP Progenitors Using Fluorine
论文作者
论文摘要
我们在两种碳增强金属贫困（CEMP）星星中提出了新的氟丰度估计，HE 1429-0551和HE 1305+0007。 HE 1429-0551在缓慢的中子捕获过程（S过程）元素（CEMP-S）中也充满了浓度，并且在缓慢和快速的中子捕获过程元素（CEMP-S/R）中都增强了1305+0007。 F的丰度估计值是从HF分子在23358.6 a上使用高分辨率红外光谱在4m级Lowell Discovery望远镜上获得的高分辨率红外光谱（IGRINS）得出的。我们的结果包括[F）= +3.93（[f/fe] = +1.90）的1429-0551在[[Fe/h] = -2.53的1429-0551中进行了F次数的测量，而A（f）<+3.28（f）<+3.28（[f/fe] <+1.00）的1305 +0007的F上限我们在HE 1429-0551中的新衍生F丰度使该对象成为检测到F的最贫困的恒星。我们将这些结果与文献价值和最新的CEMP-S模型预测进行了仔细的比较，包括详细的AGB核合成和二元进化。 HE 1429-0551的建模氟丰度与我们观察到的丰度合理一致，尽管略高于我们观察到的值。对于HE 1429-0551，我们的发现在主要同伴在热脉冲阶段的传质中支持了这种情况。与AGB模型相比，我们在1305+0007中估计的上限以及文献的数据显示出很大的差异。差异主要是由于模型努力繁殖的同时S-和R-Process元素增强。
We present new fluorine abundance estimations in two carbon enhanced metal-poor (CEMP) stars, HE 1429-0551 and HE 1305+0007. HE 1429-0551 is also enriched in slow neutron-capture process (s-process) elements, a CEMP-s, and HE 1305+0007 is enhanced in both, slow and rapid neutron-capture process elements, a CEMP-s/r. The F abundances estimates are derived from the vibration-rotation transition of the HF molecule at 23358.6 A using high-resolution infrared spectra obtained with the Immersion Grating Infrared Spectrometer (IGRINS) at the 4m-class Lowell Discovery Telescope. Our results include a F abundance measurement in HE 1429-0551 of A(F) = +3.93 ([F/Fe] = +1.90) at [Fe/H] = -2.53, and a F upper limit in HE 1305+0007 of A(F) < +3.28 ([F/Fe] < +1.00) at [Fe/H] = -2.28. Our new derived F abundance in HE 1429-0551 makes this object the most metal-poor star where F has been detected. We carefully compare these results with literature values and state-of-the-art CEMP-s model predictions including detailed AGB nucleosynthesis and binary evolution. The modelled fluorine abundance for HE 1429-0551 is within reasonable agreement with our observed abundance, although is slightly higher than our observed value. For HE 1429-0551, our findings support the scenario via mass transfer by a primary companion during its thermally-pulsing phase. Our estimated upper limit in HE 1305+0007, along with data from the literature, shows large discrepancies compared with AGB models. The discrepancy is principally due to the simultaneous s- and r-process element enhancements which the model struggles to reproduce.
