Title: Zippers and Twisters: Planes of Satellite Galaxies Emerge from Whirling and Shocking Gas Streams in the Cosmic Web Show Chinese title

Title: 拉链和扭转者：宇宙网中旋转和冲击的气体流形成了卫星星系的平面

Abstract: We investigate dwarf satellite systems around Milky Way analogs in the NewHorizon simulation. Using simple estimators limiting over-detection, we identify planes of satellites comparable to observations in $30\%$ to $70\%$ of cases. The full sample is strongly biased towards arrangements more elongated and co-rotating than their dark-matter host, as early as $z = 1$. We identify cosmic filaments and relics of local gas streams outside each system at $z \approx 0$ with DisPerSE. We find that the thinner the local stream plane, the thinner the system is. The two align significantly for planar systems. Streams around isotropic systems are not planar. Our analysis reveals two plane types. Ultrathin planes lie orthogonally to their single nearest cosmic filament and align to coherent vortical flows within 3 Mpc, reminiscent of $z > 2$ whirls. A second group of planar systems align to their cosmic filaments. All planes are found in single cosmic filaments skirted by coherent vortical whirls while isotropic systems are found in turbulent flows at the intersection of filaments. We conclude that planes are frequent in $\Lambda CDM$ simulations providing the cosmic environment is resolved. Tracking filaments back in time, we show a tight connection between a single, stable filament down to $z \approx 0$ and the existence of a plane. "In-filament" planes typically get enhanced by a single, edge-on filament merger at $z < 2$ (zipper) while "vertical" planes' filaments undergo single twisters (high-orbital momentum zippers) preventing the formation of a core along the filament. In contrast, isotropic systems' filaments undergo multiple misaligned mergers. Show Chinese abstract

Abstract: 我们研究了新地平线模拟中类似银河系的矮卫星系统。通过使用简单的估计器限制过检测，我们在$30\%$到$70\%$的情况下识别出与观测结果相当的卫星平面。从$z = 1$开始，整个样本强烈偏向于比其暗物质宿主更拉长且共转的排列方式。在$z \approx 0$使用 DisPerSE 识别每个系统外部的宇宙细丝和局部气体流遗迹。我们发现局部流平面越薄，系统就越薄。对于平面系统，两者显著对齐。各向同性系统的周围流不是平面的。我们的分析揭示了两种平面类型。超薄平面垂直于其最近的单个宇宙细丝，并在 3 兆秒差距范围内与协调的涡流流动对齐，类似于$z > 2$旋涡。另一组平面系统与其宇宙细丝对齐。所有平面都位于由协调涡流漩涡环绕的单个宇宙细丝上，而各向同性系统则位于细丝交叉点的湍流中。我们得出结论，在$\Lambda CDM$模拟中，只要宇宙环境被解析，平面就普遍存在。回溯追踪细丝的时间，我们展示了单个稳定细丝与平面存在的紧密联系，直到$z \approx 0$。 “内部平面”通常会在$z < 2$（拉链）处通过一次边缘合并而增强，而“垂直平面”的细丝会经历单次扭转（高轨道动量拉链），阻止沿细丝形成核心。相比之下，各向同性系统的细丝会经历多次方向不一致的合并。