We use the EAGLE cosmological simulations to study the evolution of the vertical velocity dispersion of cold gas, $σ_{z}$, in central disc galaxies and its connection to stellar feedback, gravitational instabilities, cosmological gas accretion and galaxy mergers. To isolate the impact of feedback, we analyse runs that turn off stellar and (or) AGN feedback in addition to a run that includes both. The evolution of $σ_z$ and its dependence on stellar mass and star formation rate in EAGLE are in good agreement with observations. Galaxies hosted by haloes of similar virial mass, $\rm M_{200}$, have similar $σ_z$ values even in runs where feedback is absent. The prevalence of local instabilities in discs is uncorrelated with $σ_z$ at low redshift and becomes only weakly correlated at high redshifts and in galaxies hosted by massive haloes. $σ_z$ correlates most strongly with the specific gas accretion rate onto the disc as well as with the degree of misalignment between the inflowing gas and the disc's rotation axis. These correlations are significant across all redshifts and halo masses, with misaligned accretion being the primary driver of high gas turbulence at redshifts $z \lesssim 1$ and for halo masses $\rm M_{200} \lesssim 10^{11.5} M_{\odot}$. Galaxy mergers increase $σ_z$, but because they are rare in our sample, they play only a minor role in its evolution. Our results suggest that the turbulence of cold gas in EAGLE discs results from a complex interplay of different physical processes whose relative importance depends on halo mass and redshift.
The SAMI Galaxy Survey: Gas velocity dispersions in low-$z$ star-forming galaxies and the drivers of turbulence
我们推断的内在电离气体运动学的383恒星形成星系在一个范围内的综合恒星形成率（SFR $\in [10^{-3}, 10^2]$ M $_\odot$年$^{-1}$）在$z \lesssim 0.1$使用一致的三维正演模拟技术。总样本是SAMI星系巡天和SAMO巡天的星系组合。对于典型的低$z$星系从SAMI星系巡天，我们发现的垂直速度色散（$σ_{v, z}$）是正相关的恒星形成率，恒星质量，HI气体质量和旋转速度的措施。最大的相关性是与恒星形成率表面密度（$Σ_\text{SFR}$）。使用总样本，我们发现$σ_{v, z}$在范围SFR $\in$ [ $10^{-3}$，1] M $_\odot$ yr $^{-1}$从$17\pm3$ km s $^{-1}$到$24\pm5$ km s $^{-1}$内缓慢增加，然后急剧增加到$σ_{v, z}$ $\sim 80$ km s $^{-1}$，对于SFR $\gtrsim 1$ M $_\odot$ yr $^{-1}$。这与最近的理论模型是一致的，该模型提出了由恒星形成反馈过程驱动的$σ_{v, z}$地板，在较高的SFR下，由气体通过圆盘的引力传输驱动的$σ_{v, z}$向上翻转。
Kinematics of H I and O VI Absorbers: Insights into the Turbulence Driver of the Multiphase Circumgalactic Medium
Tsinghua University（清华大学）；The University of Chicago（芝加哥大学）；Peking University（北京大学）；Zentrum für Astronomie der Universität Heidelberg, Astronomisches Rechen-Institut（海德堡大学天文中心，天文计算研究所）
Bulk vs. turbulent motions at the centres of galaxy clusters: AGN-driven turbulence according to TNG-Cluster
Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Fakultät für Physik und Astronomie, Universität Heidelberg（海德堡大学物理与天文学院）；Département de Physique, Université de Montréal（蒙特利尔大学物理系）；Universität Heidelberg, Zentrum für Astronomie, ITA（海德堡大学天文学中心）；Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen（海德堡大学跨学科科学计算中心）
The driving mode of turbulence in disc galaxy simulations with adaptive mesh refinement
Research School of Astronomy and Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Lund Observatory, Division of Astrophysics, Department of Physics, Lund University（隆德大学物理系天体物理学部隆德天文台）
