中子捕获元件记录了圆盘随时间的有序化学演化
Neutron-capture elements record the ordered chemical evolution of the disc over time
摘要：
探测不同核合成通道的化学丰度的集合可以用来建立对银河系化学和结构演化的全面理解。利用GALAH DR 3数据，我们分别通过研究$\sim$ 50，000颗红巨星的[Fe/H]、[ $α$ /Fe]、[Ba/Fe]和[Eu/Fe]化学组成，来追踪超新星Ia、超新星II、渐近巨星分支星、中子星合并和/或双星核合成源的富集。利用[Fe/H]-[ $α$ /Fe]小盒作为超新星贡献的有效参考框架，我们计算了[Ba/Fe]和[Eu/Fe]的丰度-年龄剖面。我们的结果揭示了这些年龄-丰度关系在[Fe/H]-[ $α$ /Fe]平面上的变化。在细胞内，我们发现负的年龄-[Ba/Fe]关系和平坦的年龄-[Eu/Fe]关系。在整个细胞中，我们看到年龄-[Ba/Fe]关系的斜率平滑地演变，而[Eu/Fe]关系的幅度变化。随后，我们使用灵活的Chempy银河系化学演化（GCE）代码，使用平均[Fe/H]，[Mg/Fe]，[Ba/Fe]和年龄值的恒星星族在[Fe/H]，[Mg/Fe]和年龄空间的理论设置模型我们的经验发现。我们发现，在一个区域的框架内，合奏的GCE模型参数的变化来解释的数据。使用现今的轨道从\textit{Gaia} EDR 3测量，我们推断，GCE模型参数，它设置所观察到的化学丰度分布，在平均轨道半径系统地变化。根据我们的建模假设，观察到的化学丰度是一致的，在高质量端的初始质量函数（IMF）在整个光盘，其中IMF是更重的顶部朝向内盘和更重的底部在外盘的小梯度。
英文摘要：
An ensemble of chemical abundances probing different nucleosynthetic channels can be leveraged to build a comprehensive understanding of the chemical and structural evolution of the Galaxy. Using GALAH DR3 data, we seek to trace the enrichment by the supernovae Ia, supernovae II, asymptotic giant branch stars, and neutron-star mergers and/or collapsars nucleosynthetic sources by studying the [Fe/H], [$α$/Fe], [Ba/Fe], and [Eu/Fe] chemical compositions of $\sim$50,000 red giant stars, respectively. Employing small [Fe/H]-[$α$/Fe] cells, which serve as an effective reference-frame of supernovae contributions, we characterise the abundance-age profiles for [Ba/Fe] and [Eu/Fe]. Our results disclose that these age-abundance relations vary across the [Fe/H]-[$α$/Fe] plane. Within cells, we find negative age-[Ba/Fe] relations and flat age-[Eu/Fe] relations. Across cells, we see the slope of the age-[Ba/Fe] relations evolve smoothly and the [Eu/Fe] relations vary in amplitude. We subsequently model our empirical findings in a theoretical setting using the flexible Chempy Galactic chemical evolution (GCE) code, using the mean [Fe/H], [Mg/Fe], [Ba/Fe], and age values for stellar populations binned in [Fe/H], [Mg/Fe], and age space. We find that within a one-zone framework, an ensemble of GCE model parameters vary to explain the data. Using present day orbits from \textit{Gaia} EDR3 measurements we infer that the GCE model parameters, which set the observed chemical abundance distributions, vary systematically across mean orbital radii. Under our modelling assumptions, the observed chemical abundances are consistent with a small gradient in the high mass end of the initial mass function (IMF) across the disc, where the IMF is more top heavy towards the inner disc and more bottom heavy in the outer disc.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
