Figuring Out Gas & Galaxies in Enzo (FOGGIE). IV. The Stochasticity of Ram Pressure Stripping in Galactic Halos
Figuring Out Gas & Galaxies in Enzo (FOGGIE). IV. The Stochasticity of Ram Pressure Stripping in Galactic Halos
复制标题
计算出气体
DOI：
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发表时间：
2020
影响因子：
4.9
通讯作者：
E. Tollerud
中科院分区：
文献类型：
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作者：
R. Simons;M. Peeples;J. Tumlinson;B. O’Shea;Britton D. Smith;L. Corlies;C. Lochhaas;Yonggang Zheng;R. Augustin;D. Prasad;G. Snyder;E. Tollerud
我们从恩佐(Foggie)的“弄清楚气体和星系”项目出发，研究了模拟银河系晕中的冲压剥离。由于Foggie的新改进方案，这些模拟在其环星系介质(CGM)中的整个气体中达到了亚千帕秒的分辨率。每个晕的CGM在其体积上的密度和速度都跨越了一个很大的动态范围-分别约为6度和1,000公里S−1-转化为给予相互作用的卫星的拉姆压力范围为5度。由于CGM气体密度和速度场在千帕秒尺度上的变化，模拟的CGM在z=2时的局部冲压是高度随机的。因此，冲压剥离的效果在很大程度上取决于卫星通过CGM的具体路径。单个卫星的冲压历史通常是不可预测的，并且与其相对于宿主星系的接近矢量没有很好的相关性。冲撞压力对模拟卫星的累积影响只由几个短而强的冲量主导-平均而言，通过冲撞压力获得的总表面动量的90%是在总轨道时间的20%或更少时间内传递的。这些结果揭示了在高红移的类似银河系的晕中，冲压剥离的一种不稳定的模式-这种模式不被环星系介质的平滑的球面平均流体静力学模型捕捉到。
We study ram pressure stripping in simulated Milky Way-like halos at from the Figuring Out Gas & Galaxies in Enzo (FOGGIE) project. These simulations reach subkiloparsec resolution throughout the gas in their circumgalactic medium (CGM) 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−1, respectively—translating into a 5 dex range in ram pressure imparted to interacting satellites. The local ram pressure of the simulated CGM at z = 2 is highly stochastic, owing to kiloparsec-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 hydrostatic model of the circumgalactic medium.
DOI：
10.3847/1538-4357/ab378f
发表时间：
2018-11
期刊：
The Astrophysical Journal
影响因子：
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作者：
C. Hummels;Britton D. Smith;P. Hopkins;B. O’Shea;Devin W. Silvia;J. Werk;N. Lehner;J. Wise;D. Collins;Iryna S. Butsky
通讯作者：
C. Hummels;Britton D. Smith;P. Hopkins;B. O’Shea;Devin W. Silvia;J. Werk;N. Lehner;J. Wise;D. Collins;Iryna S. Butsky