论文标题
电子模拟中的球状簇金属分布
Globular cluster metallicity distributions in the E-MOSAICS simulations
论文作者
论文摘要
星系中球状簇（GC）系统的金属性分布是对任何GC形成方案的关键测试。在这项工作中，我们调查了鹰（Eagle（E-Mosaics）在宇宙学模拟中的建模星簇种群组装中的星系中的GC金属性分布）的预测（E-Mosaics）模拟，对代表性的宇宙学量（$ L = 34.4 $ commoving MPC）进行了模拟。我们发现，来自基金会E-Mosaics GC形成模型的预测的GC金属性分布和中值金属度很好地同意观察到的分布，除了带有群众的星系$ M_ \ ast \ ast \ sim 2 \ sim 2 \ times 10^{10} $ m $ _ \ m $ _ \ odot $，其中包含过度含有金属富含金属的金属含量的GCS。具有双峰GC金属性分布的星系的预测部分（总计$ 37 \ pm 2 $ 2 $ 2 $ 2 $ $ 45 \ pm 7 $ 7 $ $ m_ \ ast> 10^{10.5} $ m $ $ _ \ odot $与观察分数（$ 44^{+10}} $ 9} _ { - 9} _ { - 9}金属贫困和金属丰富的峰。我们表明，对于大型星系（$ m_ \ ast> 10^{10} $ m $ _ \ odot $），Bimodal GC分布主要是由于最初单次分布的群集破坏而导致的，而不是由于群集形成过程而导致的。基于银河系中带有GC样恒星的田间恒星的分布，我们建议银河系的双峰GC金属性分布GC也是由于聚类破坏而不是形成过程而发生的。我们得出的结论是，不需要单独的地层过程来解释金属贫困和金属丰富的GC，并且可以将GC视为年轻大型巨星簇的幸存类似物，这些类似物很容易被观察到今天在当地宇宙中形成。
The metallicity distributions of globular cluster (GC) systems in galaxies are a critical test of any GC formation scenario. In this work, we investigate the predicted GC metallicity distributions of galaxies in the MOdelling Star cluster population Assembly In Cosmological Simulations within EAGLE (E-MOSAICS) simulation of a representative cosmological volume ($L = 34.4$ comoving Mpc). We find that the predicted GC metallicity distributions and median metallicities from the fiducial E-MOSAICS GC formation model agree well the observed distributions, except for galaxies with masses $M_\ast \sim 2 \times 10^{10}$ M$_\odot$, which contain an overabundance of metal-rich GCs. The predicted fraction of galaxies with bimodal GC metallicity distributions ($37 \pm 2$ per cent in total; $45 \pm 7$ per cent for $M_\ast > 10^{10.5}$ M$_\odot$) is in good agreement with observed fractions ($44^{+10}_{-9}$ per cent), as are the mean metallicities of the metal-poor and metal-rich peaks. We show that, for massive galaxies ($M_\ast > 10^{10}$ M$_\odot$), bimodal GC distributions primarily occur as a result of cluster disruption from initially-unimodal distributions, rather than as a result of cluster formation processes. Based on the distribution of field stars with GC-like abundances in the Milky Way, we suggest that the bimodal GC metallicity distribution of Milky Way GCs also occurred as a result of cluster disruption, rather than formation processes. We conclude that separate formation processes are not required to explain metal-poor and metal-rich GCs, and that GCs can be considered as the surviving analogues of young massive star clusters that are readily observed to form in the local Universe today.
