TNG50模拟中类MW星系的DM晕形态类型：简单、扭曲或拉伸
DM halo morphological types of MW-like galaxies in the TNG50 simulation: Simple, Twisted, or Stretched
摘要：
利用TNG 50模拟对25个类银河星系中的暗物质晕的形状进行了全面的分析。使用封闭体积迭代法（EVIM），我们推断出一个扁圆三轴形状的DM晕与中位数$T \simeq 0.24 $。我们将DM晕分为3个不同的类别。简单的晕（32%的人口）建立主轴，其顺序的大小不随半径变化，其方向几乎是固定的整个晕。扭曲晕（32%的人口），经验水平的逐步旋转整个径向剖面。最后，拉伸晕（人口的36%）展示了其主轴长度的拉伸，其中不同特征值的顺序随半径而变化。随后，光晕经历$\sim$ 90度的“旋转”，其中发生拉伸。可视化的3D椭球的每个晕，第一次，我们报告的迹象重新定向椭球在扭曲和拉伸晕。我们研究的影响，重子物理DM晕形状通过比较暗物质只（DMO）模拟。这表明一个三轴（长轴）晕。我们分析了在水力和DMO模拟中，子结构对DM晕形状的影响，并确认它们的影响是次主导的。我们研究了样本中卫星的分布。在简单晕和扭曲晕中，卫星角动量与星系角动量的夹角随半径的增大而增大。然而，拉伸晕显示出平坦的角度分布。将我们的理论结果与文献中的观测结果相叠加，可以建立一个公平的协议。
英文摘要：
We present a comprehensive analysis of the shape of dark matter (DM) halos in a sample of 25 Milky Way-like galaxies in TNG50 simulation. Using an Enclosed Volume Iterative Method (EVIM), we infer an oblate-to-triaxial shape for the DM halo with the median $T \simeq 0.24 $. We group DM halos in 3 different categories. Simple halos (32% of population) establish principal axes whose ordering in magnitude does not change with radius and whose orientations are almost fixed throughout the halo. Twisted halos (32% of population), experience levels of gradual rotations throughout their radial profiles. Finally, stretched halos (36% of population) demonstrate a stretching in their principal axes lengths where the ordering of different eigenvalues change with radius. Subsequently, the halo experiences a "rotation" of $\sim$90 deg where the stretching occurs. Visualizing the 3D ellipsoid of each halo, for the first time, we report signs of re-orienting ellipsoid in twisted and stretched halos. We examine the impact of baryonic physics on DM halo shape through a comparison to dark matter only (DMO) simulations. This suggests a triaxial (prolate) halo. We analyze the impact of substructure on DM halo shape in both hydro and DMO simulations and confirm that their impacts are subdominant. We study the distribution of satellites in our sample. In simple and twisted halos, the angle of satellites' angular momentum with galaxy's angular momentum grows with radius. However, stretched halos show a flat distribution of angles. Overlaying our theoretical outcome on the observational results presented in the literature establishes a fair agreement.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
