论文标题
部分可观测时空混沌系统的无模型预测
Reliability and limitations of inferring birth radii in the Milky Way disk
论文作者
论文摘要
银河考古学的最终目标之一是恢复观察到的恒星的出生半径。一种推断出生半径和ISM金属性演变的方法假设在任何给定的外观时间时，ISM金属性与半径之间的线性关系。在这里，我们通过使用Nihao-UHD项目的4个Zoom-In宇宙流体动力学模拟来测试该假设的可靠性。我们发现，只有当恒星磁盘开始形成时，才能推断出精确的出生半径，对于我们的模型星系发生了〜10 Gyr，与银河系的最新估计一致。在以后的时间，随着恒星运动变得更加有序并且ISM金属度的方位角变化开始下降，ISM金属度和半径之间的线性相关性增加。中央条的形成和合并的扰动可以分别增加内部和外部磁盘中的这种不确定性。
Recovering the birth radii of observed stars in the Milky Way is one of the ultimate goals of Galactic Archaeology. One method to infer the birth radius and the evolution of the ISM metallicity assumes a linear relation between the ISM metallicity with radius at any given look-back time. Here we test the reliability of this assumption by using 4 zoom-in cosmological hydrodynamic simulations from the NIHAO-UHD project. We find that one can infer precise birth radii only when the stellar disk starts to form, which for our modeled galaxies happens ~ 10 Gyr ago, in agreement with recent estimates for the Milky Way. At later times the linear correlation between the ISM metallicity and radius increases, as stellar motions become more ordered and the azimuthal variations of the ISM metallicity start to drop. The formation of a central bar and perturbations from mergers can increase this uncertainty in the inner and outer disk, respectively.
