Discrete Effects in Stellar Feedback: Individual Supernovae, Hypernovae, and IMF Sampling in Dwarf Galaxies
Discrete Effects in Stellar Feedback: Individual Supernovae, Hypernovae, and IMF Sampling in Dwarf Galaxies
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恒星反馈中的离散效应：矮星系中的单个超新星、超新星和 IMF 采样
DOI：
10.1093/mnras/sty1928
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发表时间：
2018
影响因子：
4.8
通讯作者：
Wheeler, Coral
中科院分区：
文献类型：
--
作者：
Su, Kung-Yi;Hopkins, Philip F;Hayward, Christopher C;Ma, Xiangcheng;Boylan-Kolchin, Michael;Kasen, Daniel;Kereš, Dušan;Faucher-Giguère, Claude-André;Orr, Matthew E;Wheeler, Coral
利用FIRE-2（Feedback In Realistic Environments，真实环境中的反馈）项目的高分辨率模拟，我们研究了恒星反馈过程的离散性对星系演化和星际介质（ISM）性质的影响。我们特别考虑了超新星（SNe）的离散化，包括超新星（HNe），并对初始质量函数（IMF）进行采样。我们研究这些过程中的宇宙学模拟的矮星系= 0恒星质量（晕质量）。我们表明，个别SNe的离散性质（而不是一个模型，其中他们的能量/动量沉积是连续的超时，类似于恒星风）是至关重要的，在产生一个合理的ISM结构和星系风，并在调节矮恒星质量。然而，一旦SNe离散化，占IMF采样的影响，如辐射反馈和恒星质量损失（而不是采用IMF平均率）的连续机制，对星系尺度的性质有微弱的影响。我们还考虑了稀有氦氖事件的影响与能量。HNe的效应类似于SNe集群爆炸的效应--这已经在我们的默认模拟设置中被捕获--并且不会淬灭星星的形成（前提是HNe不占SNe总能量预算的主导地位），这表明今天在超微弱的矮星中应该可以观察到HNe产额产物。
Using high-resolution simulations from the FIRE-2 (Feedback In Realistic Environments) project, we study the effects of discreteness in stellar feedback processes on the evolution of galaxies and the properties of the interstellar medium (ISM). We specifically consider the discretization of supernovae (SNe), including hypernovae (HNe), and sampling the initial mass function (IMF). We study these processes in cosmological simulations of dwarf galaxies with= 0 stellar masses(halo masses). We show that the discrete nature of individual SNe (as opposed to a model in which their energy/momentum deposition is continuous overtime, similar to stellar winds) is crucial in generating a reasonable ISM structure and galactic winds and in regulating dwarf stellar masses. However, once SNe are discretized, accounting for the effects of IMF sampling on continuous mechanisms such as radiative feedback and stellar mass-loss (as opposed to adopting IMF-averaged rates) has weak effects on galaxy-scale properties. We also consider the effects of rare HNe events with energies. The effects of HNe are similar to the effects of clustered explosions of SNe – which are already captured in our default simulation setup – and do not quench star formation (provided that the HNe do not dominate the total SNe energy budget), which suggests that HNe yield products should be observable in ultra-faint dwarfs today.