Modeling for Stellar Feedback in Galaxy Formation Simulations
Modeling for Stellar Feedback in Galaxy Formation Simulations
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DOI：
10.3847/1538-4357/836/2/204
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
A. N'unez;J. Ostriker;T. Naab;L. Oser;Chia-Yu Hu;E. Choi
中科院分区：
文献类型：
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作者：
A. N'unez;J. Ostriker;T. Naab;L. Oser;Chia-Yu Hu;E. Choi
在星系形成模拟中，有各种启发式方法来模拟未分解的超新星(SN)反馈，以再现螺旋星系的形成和气体到恒星的整体低效转换。然而，一些模型需要依赖于分辨率的缩放。我们提出了一个亚分辨率模型，它代表了超新星爆炸波演化的三个主要阶段--自由扩展、能量守恒的Sedov-Taylor和动量守恒的扫雪器--能量标度来自均匀和多相介质中的高分辨率星际介质模拟。我们考虑了在多相介质中随着冷却半径随热体积分数As的变化而显著增强的SN残留物传播的影响。我们还包括来自年轻的大质量恒星和AGB恒星的风，大质量恒星加热的斯特朗格伦球体气体，以及一种限制气体冷却的机制，这种冷却是由密集的H II区域的辐射复合驱动的。我们给出了对孤立的类银河系系统的初步测试，这些系统是用基于Gadget的代码SPHga和改进的SPH处方模拟的。与纯热SN输入相比，该模型在早期显著抑制了恒星的形成，恒星形成在时间和空间上都延长了，与观测结果更符合。与纯热SN反馈的模型相比，恒星质量的一半聚集年龄增加了2.4倍，质量加载参数和气体流出速率增加了2倍。模拟结果在(1.3-130)×104太阳质量范围内粒子质量变化两个数量级时收敛。
Various heuristic approaches to model unresolved supernova (SN) feedback in galaxy formation simulations exist to reproduce the formation of spiral galaxies and the overall inefficient conversion of gas into stars. Some models, however, require resolution-dependent scalings. We present a subresolution model representing the three major phases of supernova blast wave evolution—free expansion, energy-conserving Sedov–Taylor, and momentum-conserving snowplow—with energy scalings adopted from high-resolution interstellar-medium simulations in both uniform and multiphase media. We allow for the effects of significantly enhanced SN remnant propagation in a multiphase medium with the cooling radius scaling with the hot volume fraction, , as . We also include winds from young massive stars and AGB stars, Strömgren sphere gas heating by massive stars, and a mechanism that limits gas cooling that is driven by radiative recombination of dense H ii regions. We present initial tests for isolated Milky Way-like systems simulated with the Gadget-based code SPHgal with improved SPH prescription. Compared to pure thermal SN input, the model significantly suppresses star formation at early epochs, with star formation extended both in time and space in better accord with observations. Compared to models with pure thermal SN feedback, the age at which half the stellar mass is assembled increases by a factor of 2.4, and the mass-loading parameter and gas outflow rate from the galactic disk increase by a factor of 2. Simulation results are converged for a variation of two orders of magnitude in particle mass in the range (1.3–130) × 104 solar masses.