标题： 用丰度聚类追踪恒星的诞生特性 显示英文标题

标题： Tracing birth properties of stars with abundance clustering

摘要： 为了理解银河系盘的形成和演化，我们必须将其当前特性与其过去联系起来。 我们探索流体动力学宇宙学模拟，以研究恒星的化学丰度如何可能与其起源相关联。 使用两种类似银河系的模拟中丰度测量的层次聚类，这些模拟具有分布和稳定的恒星形成历史，我们发现恒星的丰度簇在出生地（$R_\text{birth}$）和时间（年龄）上包含不同的组。 模拟观测丰度误差（0.05 dex），我们发现要追踪（$R_\text{birth}$，年龄）的离散组需要一个大的丰度向量。 使用15个元素的丰度（Fe，O，Mg，S，Si，C，P，Mn，Ne，Al，N，V，Ba，Cr，Co），最多可以定义$\approx$10个簇，在（$R_\text{birth}$，年龄）中有$\approx$25%的重叠。 我们构建了一个简单的模型，以表明可以从丰度中推断出恒星的年龄和$R_\text{birth}$，精度分别为$\pm$0.06 Gyr 和$\pm$1.17 kpc。 我们发现，在第三个模拟中，丰度聚类无效，其中低-$\alpha$恒星在盘中分布，而早期高-$\alpha$恒星更快速地在团块中形成，并随着其组成恒星演化而向银河系中心沉降，从而丰富星际介质。 然而，这种形成路径导致了[$\alpha$/Fe]-[Fe/H]平面上的大年龄弥散，这与银河系的观测特性不一致。 我们得出结论，丰度聚类是一种有前景的方法，用于绘制我们银河系的历史。 显示英文摘要

摘要： To understand the formation and evolution of the Milky Way disk, we must connect its current properties to its past. We explore hydrodynamical cosmological simulations to investigate how the chemical abundances of stars might be linked to their origins. Using hierarchical clustering of abundance measurements in two Milky Way-like simulations with distributed and steady star formation histories, we find that abundance clusters of stars comprise different groups in birth place ($R_\text{birth}$) and time (age). Simulating observational abundance errors (0.05 dex), we find that to trace discrete groups of ($R_\text{birth}$, age) requires a large vector of abundances. Using 15-element abundances (Fe, O, Mg, S, Si, C, P, Mn, Ne, Al, N, V, Ba, Cr, Co), up to $\approx$ 10 clusters can be defined with $\approx$ 25% overlap in ($R_\text{birth}$, age). We build a simple model to show that it is possible to infer a star's age and $R_\text{birth}$ from abundances with precisions of $\pm$0.06 Gyr and $\pm$1.17 kpc respectively. We find that abundance clustering is ineffective for a third simulation, where low-$\alpha$ stars form distributed in the disc and early high-$\alpha$ stars form more rapidly in clumps that sink towards the galactic center as their constituent stars evolve to enrich the interstellar medium. However, this formation path leads to large age-dispersions across the [$\alpha$/Fe]-[Fe/H] plane, which is inconsistent with the Milky Way's observed properties. We conclude that abundance clustering is a promising approach toward charting the history of our Galaxy.