Galaxy cold gas contents in modern cosmological hydrodynamic simulations
Galaxy cold gas contents in modern cosmological hydrodynamic simulations
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DOI：
10.1093/mnras/staa1894
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发表时间：
2020-02
影响因子：
4.8
通讯作者：
R. Dav'e;R. Crain;A. Stevens;D. Narayanan;A. Saintonge;B. Catinella;L. Cortese
中科院分区：
文献类型：
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作者：
R. Dav'e;R. Crain;A. Stevens;D. Narayanan;A. Saintonge;B. Catinella;L. Cortese
比较了SIMBA、EAGLE和IllustrisTNG三种最新的宇宙流体力学模拟中星系原子和分子气体的性质，以及从z∼0到2的观测结果。这些模拟都依赖于相似的次分辨率规定来模拟它们不能直接表示的冷星际气体，并定性地再现了观测到的z≈0 H I和H2质量函数(分别为HIMF和H 2MF)、CO(1-0)光度函数(CORF)以及气体与恒星质量、比恒星形成率和恒星表面密度μ*的比例关系，但有一些定量上的差异。为了与COLF相比较，我们根据模拟星系的平均分子面密度和金属丰度对模拟星系应用了H2到CO的转换因子，产生了αCO的显著变化和模型之间的显著差异。使用此方法，预测的z=0Colf比预测的H2Mf与数据更符合。到z∼2，Eagle和Simba的HIMF和COLF强烈增加，而IllustrisTNG的HIMF下降，COLF演化缓慢。Eagle和SIMBA在z∼1-2重现了高LCO(1-0)星系，部分原因是αCO(z=2)∼1与αCO(z=0)∼3的中位数。考察HI、H2和CO的标度关系，它们与M*的趋势在所有模型中都得到了广泛的再现，但EAGLE在绿谷星系中产生的HI太少，IllustrisTNG和SIMBA在大质量星系中过度产生冷气体，而SIMBA在小系统中过度产生分子气体。使用排除单个活动星系核反馈模块的SIMBA变体，我们发现SIMBA的活动星系核喷流反馈主要是通过抑制$M_*\gtrsim 10^{10}{\rm\，M}_\odt$星系中的冷气体来降低z∼1→0中的冷气体含量，而X射线反馈则抑制了高μ*系统的形成。
We present a comparison of galaxy atomic and molecular gas properties in three recent cosmological hydrodynamic simulations, namely SIMBA, EAGLE, and IllustrisTNG, versus observations from z ∼ 0 to 2. These simulations all rely on similar subresolution prescriptions to model cold interstellar gas that they cannot represent directly, and qualitatively reproduce the observed z ≈ 0 H i and H2 mass functions (HIMFs and H2MFs, respectively), CO(1–0) luminosity functions (COLFs), and gas scaling relations versus stellar mass, specific star formation rate, and stellar surface density μ*, with some quantitative differences. To compare to the COLF, we apply an H2-to-CO conversion factor to the simulated galaxies based on their average molecular surface density and metallicity, yielding substantial variations in αCO and significant differences between models. Using this, predicted z = 0 COLFs agree better with data than predicted H2MFs. Out to z ∼ 2, EAGLE’s and SIMBA’s HIMFs and COLFs strongly increase, while IllustrisTNG’s HIMF declines and COLF evolves slowly. EAGLE and simba reproduce high-LCO(1–0) galaxies at z ∼ 1–2 as observed, owing partly to a median αCO(z = 2) ∼ 1 versus αCO(z = 0) ∼ 3. Examining H i, H2, and CO scaling relations, their trends with M* are broadly reproduced in all models, but EAGLE yields too little H i in green valley galaxies, IllustrisTNG and SIMBA overproduce cold gas in massive galaxies, and SIMBA overproduces molecular gas in small systems. Using SIMBA variants that exclude individual active galactic nucleus (AGN) feedback modules, we find that SIMBA’s AGN jet feedback is primarily responsible by lowering cold gas contents from z ∼ 1 → 0 by suppressing cold gas in $M_*\gtrsim 10^{10}{\rm \,M}_\odot$ galaxies, while X-ray feedback suppresses the formation of high-μ* systems.