发表机构
Institute for Theory & Computation, Center for Astrophysics — Harvard & Smithsonian; Research School for Astronomy & Astrophysics, Australian National University; ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australian National University; Department of Astronomy, University of Florida; Department of Astronomy, University of Virginia; Virginia Institute for Theoretical Astronomy, University of Virginia; The Observatories, Carnegie Institution for Science; Department of Astrophysical Sciences, Princeton University（哈佛-史密森尼天体物理中心理论计算研究所; 澳大利亚国立大学天文与天体物理研究学院; 澳大利亚国立大学三维全天空天体物理学卓越研究中心; 佛罗里达大学天文学系; 弗吉尼亚大学天文学系; 弗吉尼亚大学理论天文学研究所; 卡内基科学机构天文台; 普林斯顿大学天体物理科学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过分析 NGC 1365 的高分辨率氧丰度并结合 IllustrisTNG 模拟，揭示星系盘、棒和气体盘分别由不同时期合并事件组装的历史，证明化学考古学可追踪星系动力学演化。
AI 中文摘要
星系通过气体吸积和星系合并而成长。从单一时间快照追踪星系的动力学历史是出了名的困难。我们展示了可以利用氧丰度作为考古学示踪剂来追踪星系的动力学历史。我们推导了正面朝向的旋涡星系 NGC 1365 中 4546 个空间像素（spaxel）的气相氧丰度，空间分辨率为 175 秒差距（pc），提供了银河系之外旋涡星系最详细的化学化石记录之一。我们应用 IllustrisTNG 宇宙学模拟来分析 NGC 1365 理论模型中的化学丰度分布。在该模型中，主盘氧丰度梯度最早形成，距今 119-125 亿年前，通过多次矮星系合并形成。陡峭的内棒梯度在过去 120 亿年间缓慢形成，通过气体流入核区引发的恒星形成所进行的增丰过程。一个具有平坦氧丰度的扩展电离气体盘在更近期（59-86 亿年前）通过一次小规模合并组装而成。这项工作表明，宇宙学模拟和超高空间分辨率氧丰度相结合，可以为旋涡星系的恒星形成和合并历史提供考古学探针。
英文摘要
Galaxies build through infalling gas and galaxy mergers. Tracking the dynamical history of a galaxy from a single snapshot in time is notoriously difficult. We show that the dynamical history of a galaxy can be tracked using oxygen abundances as archeological tracers. We derive the gas-phase oxygen abundances for 4546 spaxels across the face-on spiral galaxy NGC~1365 at a spatial resolution of 175 pc, providing one of the most detailed chemical fossil records of a spiral galaxy outside our Milky Way. We apply IllustrisTNG cosmological simulations to analyse the chemical abundance distribution in a theoretical model for NGC~1365. In the model, the main disk oxygen abundance gradient formed earliest, 11.9-12.5 billion years ago via mergers with multiple dwarf galaxies. A steep inner bar gradient formed slowly over the last 12 billion years through enrichment from star formation triggered by the infall of gas into the nuclear regions. An extended ionized gas disk with flat oxygen abundances was assembled more recently (5.9-8.6 billion years ago) through a minor merger. This work indicates that cosmological simulations and ultra-high spatial resolution oxygen abundances together can provide an archaeological probe of the star formation and merger histories of spiral galaxies.
CommentsAccepted to Nature Astronomy June 2026 (nature.com/articles/s41550-026-02808-7)
Journal refNature Astronomy 2026, Volume 10, p. 892-900
DOI：10.1038/s41550-026-02808-7
