Decoding the structure and formation history of the Milky Way halo with non-equilibrium orbit-based models

用非平衡轨道模型解码银河系晕的结构和形成历史

• 批准号: ST/X004066/1
• 负责人: Eugene Vasiliev
• 金额: $ 81.09万
• 依托单位: University of Surrey
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FX004066%2F1
• 关键词: Decoding; structure; formation; history; Milky

The field of Galactic astronomy is flourishing thanks to enormous advances in observational facilities in recent years, however, the progress in the theoretical analysis and interpretation of the detailed observational picture is lagging behind.The outer parts of our Galaxy (the halo) are dominated by stars originating in other stellar systems engulfed by the Milky Way in the past, which retain important clues about the Galactic assembly history and properties of ancient accreted galaxies. These building blocks are usually identified by their coherent spatial, kinematic and chemical properties, but linking the populations of same-origin stars across the entire Galaxy is only possible with the knowledge of their orbits, which in turn depend on the gravitational potential. In turn, the orbital coherence of structures such as stellar streams is used to constrain the Galactic potential and hence the distribution of stars and dark matter, but current methods are usually restricted to stationary potentials. However, the ongoing encounter between our Galaxy and its largest satellite - the Large Magellanic Cloud - introduces significant temporal variations in the potential, disturbs the kinematics of halo stars and confounds the analysis.My project will provide solid theoretical foundation and analysis techniques for the current and upcoming large-scale surveys of the Milky Way system, and will shed light on its structure and formation history with the help of next-generation models. It will combine the techniques for finding localized structures with the underlying physical model for the evolving global gravitational field of the entire Galaxy, enabling for the first time to simultaneously identify and characterize the individual building blocks and constrain the time-dependent Galactic mass distribution. It will advance our understanding of the past and present of the Milky Way, and pave the road to a detailed exploration of other galaxies in the local Universe.

近年来，由于观测设备的巨大进步，银河系天文学领域正在蓬勃发展，然而，在理论分析和解释详细观测图像方面的进展却滞后了。（光环）由起源于过去被银河系吞没的其他恒星系统的恒星主导，它保留了关于银河系聚集历史和古代吸积星系性质的重要线索。这些积木通常通过其连贯的空间，运动学和化学特性来识别，但是将整个银河系中相同起源的恒星群体联系起来只有在知道它们的轨道的情况下才有可能，而这反过来又取决于引力势。反过来，恒星流等结构的轨道相干性被用来约束银河系的潜力，从而恒星和暗物质的分布，但目前的方法通常仅限于固定的潜力。然而，我们的银河系与其最大的卫星-大麦哲伦云之间正在进行的遭遇-引入了显着的时间变化，干扰了晕星的运动学并混淆了分析。我的项目将为当前和即将进行的银河系大规模调查提供坚实的理论基础和分析技术。并将在下一代模型的帮助下揭示其结构和形成历史。它将联合收割机结合寻找局部结构的技术与整个银河系不断演变的全球引力场的基本物理模型，首次能够同时识别和表征单个构建块并限制随时间变化的银河系质量分布。它将促进我们对银河系过去和现在的理解，并为详细探索本地宇宙中的其他星系铺平道路。