论文标题

用enzo校准恒星形成和反馈模型

Calibration of a star formation and feedback model for cosmological simulations with Enzo

论文作者

Oh, Boon Kiat, Smith, Britton D., Peacock, John A., Khochfar, Sadegh

论文摘要

我们通过对银河系大小的光环(MW)光环的71个变焦模拟介绍了结果,探索了{\ tt enzo}仿真代码中广泛使用的恒星形成和反馈模型的参数空间。我们提出了一种匹配观察结果的新型方法,在广泛的光环质量上使用功能性拟合对观测到的Baryon化妆。使用三个参数对模型MW Galaxy进行校准:星形形成效率$ \ left(f _*\右)$,恒星反馈$ \ left(ε\右)$的热能效率以及注入反馈$ \ left的区域。我们发现,更改反馈能量的数量最大程度地影响了Baryon含量。然后,我们确定两组反馈参数值,它们都可以在$ 10^{10} \,\ Mathrm {M_ \ odot} $和$ 10^{12} \,\ Mathrm {m_ mathrm {m_ \ odot} $之间重现光环的Baryonic属性。我们可以通过纳入更多参数或物理学来改善协议。如果我们选择一次专注于一个物业,我们可以获得更现实的光环baryon化妆。我们表明,使用的反馈处方对$ 10^5 \,{\ rm m_ \ odot} $和$ 10^7 \,{\ rm m_ \ odot} $之间的暗物质质量分辨率不敏感。将恒星形成标准和最佳反馈参数的相应组合形成鲜明对比,我们还强调说反馈是自一致的:要匹配相同的Baryonic属性,与恒星转换效率相对较高的气体相对较高,所需的反馈强度较低,反之亦然。最后,我们证明代码中混乱的差异可能导致恒星和重子质量的偏差约为10 \%和25 \%,从相同的初始条件演变而来。

We present results from seventy-one zoom simulations of a Milky Way-sized (MW) halo, exploring the parameter space for a widely-used star formation and feedback model in the {\tt Enzo} simulation code. We propose a novel way to match observations, using functional fits to the observed baryon makeup over a wide range of halo masses. The model MW galaxy is calibrated using three parameters: the star formation efficiency $\left(f_*\right)$, the efficiency of thermal energy from stellar feedback $\left(ε\right)$ and the region into which feedback is injected $\left(r\ {\rm and}\ s\right)$. We find that changing the amount of feedback energy affects the baryon content most significantly. We then identify two sets of feedback parameter values that are both able to reproduce the baryonic properties for haloes between $10^{10}\,\mathrm{M_\odot}$ and $10^{12}\,\mathrm{M_\odot}$. We can potentially improve the agreement by incorporating more parameters or physics. If we choose to focus on one property at a time, we can obtain a more realistic halo baryon makeup. We show that the employed feedback prescription is insensitive to dark matter mass resolution between $10^5\,{\rm M_\odot}$ and $10^7\,{\rm M_\odot}$. Contrasting both star formation criteria and the corresponding combination of optimal feedback parameters, we also highlight that feedback is self-consistent: to match the same baryonic properties, with a relatively higher gas to stars conversion efficiency, the feedback strength required is lower, and vice versa. Lastly, we demonstrate that chaotic variance in the code can cause deviations of approximately 10\% and 25\% in the stellar and baryon mass in simulations evolved from identical initial conditions.

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