Supernova feedback in a local vertically stratified medium: interstellar turbulence and galactic winds
Supernova feedback in a local vertically stratified medium: interstellar turbulence and galactic winds
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局部垂直分层介质中的超新星反馈：星际湍流和银河风
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
E. Quataert
中科院分区：
文献类型：
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作者：
D. Martizzi;D. Fielding;C. Faucher;E. Quataert
我们使用本地笛卡尔模拟与垂直重力势研究超新星（SN）反馈分层星系盘驱动湍流和发射星系风。我们的分析包括三个圆盘模型的气体表面密度范围从银河系类星系到富含气体的超亮红外星系（ULIRGs），和两个不同的SN驱动方案（随机和相关的本地气体密度）。为了隔离SN反馈的物理，我们不包括额外的反馈过程。我们发现，在这些本地框计算，SN反馈激发相对较低的质量加权气体湍流速度色散~3-7公里/秒和低风质量加载因子< 1在我们研究的所有情况下。低湍流速度和风质量负载因子预测我们的本地框计算显着低于那些建议的观测富含气体和快速恒星形成的星系，他们也在紧张局势与全球模拟的盘星系调节恒星反馈。使用数值试验和分析参数相结合，我们认为，当地的笛卡尔框不能预测银河风的属性，因为他们没有捕捉到正确的全球几何和星系的引力势。实际上，在局部模拟中，风质量载荷因子并没有得到很好的定义，因为它们随着箱高度的增加而显著下降。物理上更真实的计算（例如，包括一个全球性的银河系的潜力和光盘旋转）将可能需要充分了解光盘湍流和银河外流，即使是由SNe单独反馈的理想情况。
We use local Cartesian simulations with a vertical gravitational potential to study how supernova (SN) feedback in stratified galactic discs drives turbulence and launches galactic winds. Our analysis includes three disc models with gas surface densities ranging from Milky Way-like galaxies to gas-rich ultra-luminous infrared galaxies (ULIRGs), and two different SN driving schemes (random and correlated with local gas density). In order to isolate the physics of SN feedback, we do not include additional feedback processes. We find that, in these local box calculations, SN feedback excites relatively low mass-weighted gas turbulent velocity dispersions ~3-7 km/s and low wind mass loading factors < 1 in all the cases we study. The low turbulent velocities and wind mass loading factors predicted by our local box calculations are significantly below those suggested by observations of gas-rich and rapidly star-forming galaxies; they are also in tension with global simulations of disc galaxies regulated by stellar feedback. Using a combination of numerical tests and analytic arguments, we argue that local Cartesian boxes cannot predict the properties of galactic winds because they do not capture the correct global geometry and gravitational potential of galaxies. The wind mass loading factors are in fact not well-defined in local simulations because they decline significantly with increasing box height. More physically realistic calculations (e.g., including a global galactic potential and disc rotation) will likely be needed to fully understand disc turbulence and galactic outflows, even for the idealized case of feedback by SNe alone.
影响因子：
4.8
作者：
S. Walch;T. Naab
通讯作者：
S. Walch;T. Naab