arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.14390astro-ph.GAastro-ph.CO
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比较L-GALAXIES半解析模型和IllustrisTNG模拟中的星系形成

Comparing galaxy formation in the L-GALAXIES semi-analytical model and the IllustrisTNG simulations

Mohammadreza Ayromlou, Dylan Nelson, Robert M. Yates, Guinevere Kauffmann, Malin Renneby, Simon D. M. White

摘要:

我们进行比较,对象的对象和统计,慕尼黑半解析模型,L-Galerkin,和IllustrisTNG流体动力学模拟之间。通过运行L-Galerkin的IllustrisTNG暗物质,只有合并树,我们确定在两个模型中相同的星系。这使我们能够比较两个模型中的恒星质量、恒星形成率和星系的气体含量,以及亚晕和晕的重子含量。我们发现恒星质量函数和单个星系的恒星质量都比$\sim0.2\,$ dex更符合。另一方面,特定的恒星形成速率和气体含量可能差异更大。在$z=0$中,低质量恒星形成星系和高质量淬灭星系之间的过渡发生在恒星质量尺度上,$\sim0.5\,$ dex在IllustrisTNG中比在L-Galnik中低。illustrisTNG还产生了更多的淬火星系在更高的红移。这两个模型预测的晕重子分数接近宇宙值的集群,但IllustrisTNG预测较低的重子分数组环境。这些差异主要是由于来自恒星和超大质量黑洞的模型反馈的差异。星系团和星系群内部和周围星系的气体含量和恒星形成率有很大的不同,其中IllustrisTNG卫星的恒星形成较少,气体含量也较少。我们表明,环境过程,如冲压压力剥离更强,操作到更大的距离和更广泛的主机质量范围在IllustrisTNG。我们认为,治疗星系演化的半解析模型需要改进的处方,更准确地捕捉当地的环境影响。

英文摘要:

We perform a comparison, object-by-object and statistically, between the Munich semi-analytical model, L-Galaxies, and the IllustrisTNG hydrodynamical simulations. By running L-Galaxies on the IllustrisTNG dark matter-only merger trees, we identify the same galaxies in the two models. This allows us to compare the stellar mass, star formation rate and gas content of galaxies, as well as the baryonic content of subhaloes and haloes in the two models. We find that both the stellar mass functions and the stellar masses of individual galaxies agree to better than $\sim0.2\,$dex. On the other hand, specific star formation rates and gas contents can differ more substantially. At $z=0$ the transition between low-mass star-forming galaxies and high-mass, quenched galaxies occurs at a stellar mass scale $\sim0.5\,$dex lower in IllustrisTNG than in L-Galaxies. IllustrisTNG also produces substantially more quenched galaxies at higher redshifts. Both models predict a halo baryon fraction close to the cosmic value for clusters, but IllustrisTNG predicts lower baryon fractions in group environments. These differences are due primarily to differences in modelling feedback from stars and supermassive black holes. The gas content and star formation rates of galaxies in and around clusters and groups differ substantially, with IllustrisTNG satellites less star-forming and less gas-rich. We show that environmental processes such as ram-pressure stripping are stronger and operate to larger distances and for a broader host mass range in IllustrisTNG. We suggest that the treatment of galaxy evolution in the semi-analytic model needs to be improved by prescriptions which capture local environmental effects more accurately.

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