论文标题
在Enzo（Foggie）中找出气体和星系。 iv。银河系中的RAM压力剥离的随机性
Figuring Out Gas & Galaxies In Enzo (FOGGIE). IV. The Stochasticity of Ram Pressure Stripping in Galactic Halos
论文作者
论文摘要
我们研究了来自Enzo（Foggie）项目中的气体和星系的Z> = 2的模拟银河系样光环中的RAM压力剥离。由于Foggie的新颖精致方案，这些模拟在其海洋层次培养基（CGM）中达到了精美的分辨率。每个光环的CGM在其体积上的密度和速度范围广泛 - 大约6个DEX和1000 km/s，分别转化为赋予相互作用卫星的RAM压力的5个DEX范围。由于CGM气体的密度和速度场的KPC尺度变化，模拟CGM的RAM压力曲线是高度随机的。结果，RAM压力剥离的功效在很大程度上取决于卫星通过CGM所采取的特定路径。单个卫星的冲压历史通常是不可预测的，并且与宿主星系相对于其接近矢量没有很好的相关性。 RAM压力对模拟卫星的累积影响仅由几个短的强脉冲支配 - 平均而言，通过RAM压力获得的总表面动量的90％在20％或更少的总轨道时间中赋予。这些结果揭示了在高红移时在乳状路中的RAM压力剥离的不稳定模式，而这种模式并未被圆形培养基的光滑球平均模型所捕获。
We study ram pressure stripping in simulated Milky Way-like halos at z>=2 from the Figuring Out Gas & Galaxies In Enzo (FOGGIE) project. These simulations reach exquisite resolution in their circumgalactic medium (CGM) gas owing to FOGGIE's novel refinement scheme. The CGM of each halo spans a wide dynamic range in density and velocity over its volume---roughly 6 dex and 1000 km/s, respectively---translating into a 5 dex range in ram pressure imparted to interacting satellites. The ram pressure profiles of the simulated CGM are highly stochastic, owing to kpc-scale variations of the density and velocity fields of the CGM gas. As a result, the efficacy of ram pressure stripping depends strongly on the specific path a satellite takes through the CGM. The ram-pressure history of a single satellite is generally unpredictable and not well correlated with its approach vector with respect to the host galaxy. The cumulative impact of ram pressure on the simulated satellites is dominated by only a few short strong impulses---on average, 90% of the total surface momentum gained through ram pressure is imparted in 20% or less of the total orbital time. These results reveal an erratic mode of ram pressure stripping in Milky-Way like halos at high redshift---one that is not captured by a smooth spherically-averaged model of the circumgalactic medium.
