发表机构
Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales; Inria Chile Research Center; Instituto de Astrofísica de Canarias; Universidad de La Laguna; Mathematical Sciences Institute, Australian National University; Instituto de Astrofísica, Pontificia Universidad Católica de Chile; School of Mathematics and Physics, University of Surrey; Centro de Astro-ingeniería, Pontificia Universidad Católica de Chile; Centre for Astrophysics Research, University of Hertfordshire（迪亚斯波塔莱斯大学工程与科学学院天体物理研究所; 法国国家信息与自动化研究所智利研究中心; 加那利天体物理研究所; 拉古纳大学; 澳大利亚国立大学数学科学研究院; 智利天主教Pontificia大学天体物理研究所; 萨里大学数理学院; 智利天主教Pontificia大学天体工程中心; 赫特福德大学天体物理研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究比较恒星系统发育树的距离度量，发现谱距离（尤其拉普拉斯谱距离）对噪声稳健且能区分不同化学增丰历史的星族，为验证演化模拟提供新方法。
AI 中文摘要
系统发育树提供了恒星之间化学相似性的层级表示，原则上可以从中重建其演化历史。基于模拟的研究表明，在不同化学演化情景下构建的系统发育树带有可区分的结构印记，但现有方法在实践中能否检测到这一信号尚不清楚。我们评估了用于比较系统发育树的距离度量，包括经典基于树的和图论的方法，寻求对观测噪声稳健且能区分来自不同化学增丰历史星族所构建的树的度量。我们利用太阳孪生星以及与银河系（MW）盘、盖亚-香肠-天炉座（GSE）和人马座矮椭球星系（Sgr）相关的恒星的化学丰度向量构建邻接法（Neighbor-Joining）树。两项基准测试评估了在同一演化历史内输入扰动下的稳定性以及在不同恒星种群（作为不同演化历史的代理）之间的区分能力。树度量在典型不确定性量级（约2σ，或每元素约0.05 dex）的扰动下迅速饱和，并且当叶集不同时无法区分树。相比之下，谱距离随扰动幅度平滑变化，并提供了一种用于比较由不相交恒星集构建的树的标签不变方法。在所评估的谱度量中，拉普拉斯谱距离在种群对之间显示出最一致的分离，而归一化变体最弱。应用于MW、GSE和Sgr恒星时，谱度量恢复的距离排序与其已知的化学增丰历史一致。该框架还提供了一条将观测到的增丰历史与模拟进行比较的途径，以识别最能再现观测树结构的模拟。
英文摘要
Phylogenetic trees offer a hierarchical representation of chemical similarities among stars, from which their evolutionary histories can, in principle, be reconstructed. Simulation-based work suggests that phylogenetic trees built under different chemical evolution scenarios carry distinguishable structural imprints, but whether existing methods can detect this signal in practice is unclear. We evaluate distance measures, both classical tree-based and graph-theoretical, for comparing phylogenetic trees, seeking measures robust to observational noise that separate trees built from populations with distinct chemical enrichment histories. We construct Neighbor-Joining trees from chemical abundance vectors of solar twins and of stars associated with the Milky Way (MW) disk, Gaia-Sausage-Enceladus (GSE), and the Sagittarius dwarf spheroidal galaxy (Sgr). Two benchmark tests assess stability under input perturbations within the same evolutionary history and discriminative power between distinct stellar populations used as proxies for different evolutionary histories. Tree metrics rapidly saturate under perturbations of order the typical uncertainty ($\approx2σ$, or $\approx0.05$ dex per element) and fail to distinguish trees when leaf sets differ. In contrast, spectral distances vary smoothly with perturbation amplitude and provide a label-invariant method for comparing trees built from disjoint sets of stars. Among the spectral measures evaluated, the Laplacian spectral distance shows the most consistent separation across population pairs, while the normalized variant is weakest. Applied to MW, GSE, and Sgr stars, spectral measures recover a distance ordering consistent with their known chemical enrichment histories. This framework also provides a route to comparing observed enrichment histories against simulations to identify those that best reproduce the observed tree structure.
Comments13 pages, 7 figures, accepted on A&A
