Understanding the formation of the Milky Way disk

在接下来的十年里，大型银河系调查，最引人注目的是最近发射的盖亚太空任务，将提供多达10亿颗恒星的精确位置、恒星参数和运动学信息。这样的观测数据库将具有详细揭开我们银河系结构、形成和演化所需的精度，远远超过我们对其他星系的了解。然而，为了能够分析和解释即将到来的大量极其精确的数据，我们需要大幅改进的模型。在银河系恒星的相空间中发现的子结构的日益复杂需要复杂的数值模拟，其中盘不对称(例如，来自条形、螺旋线和合并卫星的引力扰动)和非平衡过程被自洽地考虑在内。因为恒星会离开它们的出生地(即径向迁移)，所以在模型中加入化学信息对于恢复银河系的进化史至关重要。原因是恒星大气的化学成分在它们的整个生命周期中都得到了保存，这可以为我们提供恒星诞生的时间和地点的线索。我提出了一个计划，该计划将开发解决所有上述问题的银河盘模型。这项研究将由莱布尼兹天体物理研究所(AIP)主办，AIP是GAIA后续设施4MOST的领导者，也是大多数主要银河系观测(RAVE、SEGUE、APOEE、GAIA-ESO)的成员。我们将使用一种新技术，将能够追踪大量化学元素的复杂化学进化模型与最先进的宇宙学模拟相结合，为不同的银河系进化场景提供测试。这个项目的最终目标是充分利用目前可用的和即将到来的观测数据和我们的模型来限制银河系的组装历史。

In the next decade large Milky Way surveys, most notably the recently launched Gaia space mission, will provide precise positions, stellar parameters and kinematics for up to 1 billion stars. Such an observational database will have the precision necessary to unravel the structure, formation and evolution of our Galaxy in detail, vastly surpassing our knowledge of other galaxies. However, to be able to analyze and interpret the large amounts of extremely precise forthcoming data, we need drastically improved models. The increasing complexity of substructure found in the phase-space of Milky Way stars calls for sophisticated numerical modeling, where disk asymmetries (e.g., gravitational perturbations from the bar, spirals, and merging satellites) and non-equilibrium processes are taken into account self-consistently. Because stars move away from their birthplaces (i.e., migrate radially), incorporating chemical information in the models is crucial for recovering the Milky Way evolutionary history. The reason for that is that the chemical composition of stellar atmospheres is preserved throughout their lifetimes, which can give us clues about when and where stars were born. I propose a program that will develop Galactic disk models addressing all of the above problems,. This research will be hosted by the Leibniz-Institut für Astrophysik (AIP), a leader of the Gaia follow-up facility 4MOST and a member of most major Galactic surveys (RAVE, SEGUE, APOGEE, Gaia-ESO). We will provide tests for different Milky Way evolutionary scenarios by using a novel technique, which combines sophisticated chemical evolution models able to trace a large number of chemical elements with state-of-the-art cosmological simulations. The ultimate goal of this project is to constrain the Milky Way assembly history, taking full advantage of currently available and forthcoming observational data and our models.