The impact of wind scalings on stellar growth and the baryon cycle in cosmological simulations
The impact of wind scalings on stellar growth and the baryon cycle in cosmological simulations
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DOI：
10.1093/mnras/staa135
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发表时间：
2019-10
影响因子：
4.8
通讯作者：
Shuiyao Huang;N. Katz;R. Dav'e;B. Oppenheimer;D. Weinberg;M. Fardal;J. Kollmeier;M. Peeples
中科院分区：
文献类型：
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作者：
Shuiyao Huang;N. Katz;R. Dav'e;B. Oppenheimer;D. Weinberg;M. Fardal;J. Kollmeier;M. Peeples
许多现象学上成功的宇宙学模拟都使用动能风来模拟星系外流。然而，关于动能风尺度的变化如何改变可观测星系性质的系统研究却很少。在这里，我们采用gadget-3模拟研究如何重子循环，恒星质量函数，和其他星系和CGM预测的变化作为一个函数的假设流出速度和缩放的质量加载因子与速度色散。我们设计我们的基准模型，以再现测量的风属性在维里半径的25%，从反馈在现实环境中的模拟。我们发现，一个强的依赖性的低质量晕与$\sigma \lt 106\mathrm {\，km\，s^{-1}}$的η <$σ5是需要匹配的恒星质量函数在$z$ > 1的暗端。此外，更快的风大大减少了风的循环，并加热了更多的光晕气体。这两种效应导致大质量晕中恒星质量增长较少，并影响晕气体的高电离吸收。我们不能同时匹配恒星的内容在z$ = 2和0在一个单一的模型，这表明一个额外的反馈源，如活动星系核可能需要在大质量星系在较低的红移，但所需的量强烈依赖于假设的外流性质。我们用我们的基准参数运行了一个50 $\mathrm{Mpc}\，h^{-1}$，2 × 5763的模拟，结果表明它与z$\mathrm {Mpc}\，h ^{-1}$，z $\mathrm {Mpc}\，h ^{-1}$，2 × 5763的恒星形成星系特性相匹配。
Many phenomenologically successful cosmological simulations employ kinetic winds to model galactic outflows. Yet systematic studies of how variations in kinetic wind scalings might alter observable galaxy properties are rare. Here we employ gadget-3 simulations to study how the baryon cycle, stellar mass function, and other galaxy and CGM predictions vary as a function of the assumed outflow speed and the scaling of the mass-loading factor with velocity dispersion. We design our fiducial model to reproduce the measured wind properties at 25 per cent of the virial radius from the Feedback In Realistic Environments simulations. We find that a strong dependence of η ∼ σ5 in low-mass haloes with $\sigma \lt 106\mathrm{\, km\, s^{-1}}$ is required to match the faint end of the stellar mass functions at $z$ > 1. In addition, faster winds significantly reduce wind recycling and heat more halo gas. Both effects result in less stellar mass growth in massive haloes and impact high ionization absorption in halo gas. We cannot simultaneously match the stellar content at $z$ = 2 and 0 within a single model, suggesting that an additional feedback source such as active galactic nucleus might be required in massive galaxies at lower redshifts, but the amount needed depends strongly on assumptions regarding the outflow properties. We run a 50 $\mathrm{Mpc}\, h^{-1}$, 2 × 5763 simulation with our fiducial parameters and show that it matches a range of star-forming galaxy properties at $z$ ∼ 0–2.