THREE-DIMENSIONAL HYDRODYNAMIC SIMULATIONS OF MULTIPHASE GALACTIC DISKS WITH STAR FORMATION FEEDBACK. I. REGULATION OF STAR FORMATION RATES
THREE-DIMENSIONAL HYDRODYNAMIC SIMULATIONS OF MULTIPHASE GALACTIC DISKS WITH STAR FORMATION FEEDBACK. I. REGULATION OF STAR FORMATION RATES
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DOI：
10.1088/0004-637x/776/1/1
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发表时间：
2013-08
期刊：
影响因子：
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通讯作者：
Chang-Goo Kim;E. Ostriker;Woong-Tae Kim
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文献类型：
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作者：
Chang-Goo Kim;E. Ostriker;Woong-Tae Kim
来自年轻恒星的能量和动量反馈对星际介质(ISM)有深远的影响，包括加热和驱动中性气体中的湍流，从而为未来的恒星形成提供燃料。最近的理论认为，这导致了一种准平衡的自调节状态，对于外层原子主导的圆盘，恒星形成的表面密度Σsfr随着ISM的重量(或中面湍流+热压)近似线性变化。我们使用三维数值流体动力学模拟来检验热、湍流和垂直动态平衡的理论预测，以及Σ稳定流对局部盘性质的隐含的函数依赖关系。我们的模型表明，所有的平衡都是快速建立的，并且平均热压和湍流压与Σ稳定压力之间的预期比例适用。对于外盘区域，这将导致，其中Σ是总气体表面密度，ρSD是恒星盘(加上暗物质)的中面密度。这一标度律的出现是因为ρSD在我们的模型中设置了垂直动力学时间(通常也包括外盘区域)。恒星形成定律中的系数与大质量恒星的比能量和动量产额成反比。我们发现热原子气体和冷原子气体的比例、湍流与热压的比例以及平均速度色散与太阳近邻和其他外盘观测结果一致。这项研究证实了之前一组模拟的结论，这组模拟包含了相同的物理处理，但仅限于ISM的径向-垂直切片。
The energy and momentum feedback from young stars has a profound impact on the interstellar medium (ISM), including heating and driving turbulence in the neutral gas that fuels future star formation. Recent theory has argued that this leads to a quasi-equilibrium self-regulated state, and for outer atomic-dominated disks results in the surface density of star formation ΣSFR varying approximately linearly with the weight of the ISM (or midplane turbulent + thermal pressure). We use three-dimensional numerical hydrodynamic simulations to test the theoretical predictions for thermal, turbulent, and vertical dynamical equilibrium, and the implied functional dependence of ΣSFR on local disk properties. Our models demonstrate that all equilibria are established rapidly, and that the expected proportionalities between mean thermal and turbulent pressures and ΣSFR apply. For outer disk regions, this results in , where Σ is the total gas surface density and ρsd is the midplane density of the stellar disk (plus dark matter). This scaling law arises because ρsd sets the vertical dynamical time in our models (and outer disk regions generally). The coefficient in the star formation law varies inversely with the specific energy and momentum yield from massive stars. We find proportions of warm and cold atomic gas, turbulent-to-thermal pressure, and mean velocity dispersions that are consistent with solar-neighborhood and other outer disk observations. This study confirms the conclusions of a previous set of simulations, which incorporated the same physics treatment but was restricted to radial-vertical slices through the ISM.