论文标题
在Fire-2宇宙学模拟中类似银河系的星系中的星系吸积事件的可观察性能
The observable properties of galaxy accretion events in Milky Way-like galaxies in the FIRE-2 cosmological simulations
论文作者
论文摘要
在宇宙的$λ$ -Cold暗物质模型中，星系部分通过积聚卫星系统形成。先前的工作已经了解了银河恒星光环中包含的这些过程的签名。这项工作用\ textit {latte}套件的Fire-2宇宙学模拟套件中的七个银河系般的星系进行了重新审视。这些模拟的分辨率允许比较M $ _ {*} $ _ {*} $ 10 $ 10 $ \ times $ \ times $$^{7} $ m $ _ {\ odot} $的贡献，从而实现了完全自我自我自我固定和相关性的卫星的可见属性分析的分析。我们的结果表明，吸积的时间和积聚卫星的恒星质量是基本参数，在合作伙伴关系中决定了这种合并$ $ $ $ $ $ $ DAY $ $ day $ the $ $ the $ the $ $ $ day $ $ the $ $ the $ $ $ n. [$α$/fe]的空间分布和[$α$/fe/h]的组成。这些参数还控制着$ z = 0 $的积聚星系的产生动力状态，导致人们期望恒星Halo的内部区域（R $ _ {\ MathRM {gc}} $ \ lyssim $ 30 kpc）应包含来自低层和较高较高质量的完全相结合的debris。此外，我们发现，在早期的较低质量卫星中，很大一部分是在外晕中积累碎片（r $ _ {\ mathrm {gc}} $ $> $ 50 kpc），这些$ 50 kpc not $ not $ not $ not $ note $ cpc均未完全分配混合，表明可以在Kinematic Surveys中鉴定出它们。我们的结果表明，随着未来的调查越来越能够映射我们的星系的外光环，他们可能会揭示长死矮星系的残留物，其对应物太微弱，无法在$ $ $ $ $ $ $ $上看到$ $ $ $ $ $ $ $。
In the $Λ$-Cold Dark Matter model of the Universe, galaxies form in part through accreting satellite systems. Previous work have built an understanding of the signatures of these processes contained within galactic stellar halos. This work revisits that picture using seven Milky Way-like galaxies in the \textit{Latte} suite of FIRE-2 cosmological simulations. The resolution of these simulations allows a comparison of contributions from satellites above M$_{*}$$\gtrsim$10$\times$$^{7}$M$_{\odot}$, enabling the analysis of observable properties for disrupted satellites in a fully self-consistent and cosmological context. Our results show that, the time of accretion and the stellar mass of an accreted satellite are fundamental parameters that in partnership dictate the resulting spatial distribution, orbital energy, and [$α$/Fe]-[Fe/H] compositions of the stellar debris of such mergers $at$ $present$ $day$. These parameters also govern the resulting dynamical state of an accreted galaxy at $z=0$, leading to the expectation that the inner regions of the stellar halo (R$_{\mathrm{GC}}$ $\lesssim$30 kpc) should contain fully phase-mixed debris from both lower and higher mass satellites. In addition, we find that a significant fraction of the lower mass satellites accreted at early times deposit debris in the outer halo (R$_{\mathrm{GC}}$ $>$50 kpc) that are $not$ fully phased-mixed, indicating that they could be identified in kinematic surveys. Our results suggest that, as future surveys become increasingly able to map the outer halo of our Galaxy, they may reveal the remnants of long-dead dwarf galaxies whose counterparts are too faint to be seen $in$ $situ$ in higher redshift surveys.
