论文标题

e-Mosaics模拟中球簇种群的运动学及其对银河系的组装历史的影响

The kinematics of globular cluster populations in the E-MOSAICS simulations and their implications for the assembly history of the Milky Way

论文作者

Trujillo-Gomez, Sebastian, Kruijssen, J. M. Diederik, Reina-Campos, Marta, Pfeffer, Joel L., Keller, Benjamin W., Crain, Robert A., Bastian, Nate, Hughes, Meghan E.

论文摘要

我们介绍了银河系(MW)球状簇(GC)运动学与E-Mosaics项目的25个银河系宇宙学模拟的详细比较。虽然MW属于模拟跨越GC的运动学分布,但与金属贫困($ [\ rm {fe/h}] <-1.2 $)和内部($ r <8 \ rmmmmmmm} $ rmm rmm rmm paster($ [\ rm {fe/h H}]相对富含金属($ [\ rm [\ rm {fe/h}]> - 1.2 $) ($ r> 8 \ rm {kpc} $)种群的质量是非典型的。为了了解这些功能的起源,我们对模拟进行了全面的统计分析,并找到了18个相关性,描述了$ l^*$星系组装及其基于其GC种群运动学的暗物质光环。之所以出现相关性,是因为积聚和原位GC的轨道分布取决于积聚卫星的质量和积聚的红移,这是在动态分数,潮汐剥离和动态加热的综合作用的驱动下。由于原位/积聚GC的运动学通过金属富含/金属贫困和内部/外部种群广泛追踪,因此观察到的GC运动学是星系组装的敏感探针。我们预测,相对于$ l^*$星系的人口,MW通过坐着的恒星形成,十几个低质量合并和$ 1.4 \ pm1.2 $早期($ z = 3.1 \ pm1.3 $)的主要合并,迅速组装了深色物质和出色的质量。快速组装期很早结束,限制了积聚恒星的比例。我们通过为MW的组装历史提供详细的定量预测来结束。

We present a detailed comparison of the Milky Way (MW) globular cluster (GC) kinematics with the 25 Milky Way-mass cosmological simulations from the E-MOSAICS project. While the MW falls within the kinematic distribution of GCs spanned by the simulations, the relative kinematics of its metal-rich ($[\rm{Fe/H}]>-1.2$) versus metal-poor ($[\rm{Fe/H}]<-1.2$), and inner ($r<8\rm{kpc}$) versus outer ($r>8\rm{kpc}$) populations are atypical for its mass. To understand the origins of these features, we perform a comprehensive statistical analysis of the simulations, and find 18 correlations describing the assembly of $L^*$ galaxies and their dark matter haloes based on their GC population kinematics. The correlations arise because the orbital distributions of accreted and in-situ GCs depend on the masses and accretion redshifts of accreted satellites, driven by the combined effects of dynamical fraction, tidal stripping, and dynamical heating. Because the kinematics of in-situ/accreted GCs are broadly traced by the metal-rich/metal-poor and inner/outer populations, the observed GC kinematics are a sensitive probe of galaxy assembly. We predict that relative to the population of $L^*$ galaxies, the MW assembled its dark matter and stellar mass rapidly through a combination of in-situ star formation, more than a dozen low-mass mergers, and $1.4\pm1.2$ early ($z=3.1\pm1.3$) major merger. The rapid assembly period ended early, limiting the fraction of accreted stars. We conclude by providing detailed quantitative predictions for the assembly history of the MW.

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