暗物质在驱动盘状星系扰动中的作用：应用于类似大麦哲伦星云-小麦哲伦星云的星系相互作用
The Role of Dark Matter in Driving Disk Perturbations: Application to LMC-SMC Like Galaxy Interactions
- University of Arizona（亚利桑那大学）
- Universidad Tecnica Federico Santa Maria（费德里科·Santa玛利亚理工大学）
- University of Maryland（马里兰大学）
- Pontificia Universidad Católica de Chile（智利天主教 Pontifical 大学）
- University of Massachusetts, Amherst（马萨诸塞大学阿默斯特分校）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究利用N体模拟和基函数展开，量化了类似LMC-SMC系统中暗物质晕和卫星星系对宿主盘扰动的贡献，发现晕四极畸变是盘翘曲的主要来源，并通过多通道奇异谱分析区分了两种力矩的影响，为暗物质理论提供了检验途径。
AI中文摘要：
暗物质（DM）模型预测，卫星星系会扭曲其宿主星系的暗物质晕。因此，卫星星系和被扭曲的暗物质晕都可能扰动宿主星系的恒星盘。大麦哲伦星云-小麦哲伦星云（LMC-SMC）系统是一个质量比约为1:10的近邻双星系，其轨道约束良好，且LMC盘的扰动特征已被充分表征。因此，该系统为检验暗物质理论提供了独特的机会，前提是能够表征暗物质晕力矩对LMC盘的影响，以及SMC的力矩。我们利用一个孤立的类似LMC-SMC相互作用的N体模拟中的晕基函数展开（BFEs），来量化SMC和LMC暗物质晕对LMC盘施加的随时间变化的力矩。我们发现，晕力矩源于四极晕畸变，而LMC盘内部（R<6千秒差距）的翘曲是探测该四极畸变最有希望的探针。我们首次构建了一个BFE来量化由SMC和晕力矩引起的LMC盘扰动。我们发现，在麦哲伦云坠入银河系之前，LMC盘就已经受到显著扰动，其翘曲的平均垂直范围约为1千秒差距。最后，我们将多通道奇异谱分析（mSSA）应用于盘BFE系数、晕四极矩以及LMC-SMC轨道的时间序列。mSSA成功地将LMC翘曲的时间演化分解为与晕和SMC相关的成分。我们的框架识别出LMC的晕畸变与盘扰动之间的相关演化，使麦哲伦云能够成为暗物质物理的精密实验室。
英文摘要：
Dark-matter (DM) models predict that satellite galaxies distort their host's DM halo. As such, both the satellite and the distorted halo can perturb the host's stellar disk. The LMC-SMC system is a nearby $\sim1:10$~mass-ratio binary with a well-constrained orbit and well-characterized LMC disk perturbations. Hence, the system offers unique opportunities to test DM theory, provided the impact of halo torques on the LMC's disk can be characterized along with the SMC's torques. We use halo Basis Function Expansions (BFEs) of an N-body simulation of an isolated LMC-SMC-like interaction to quantify the time-dependent torques exerted on the LMC's disk by the SMC and the LMC's DM halo. We find that the halo torques arise from the quadrupole halo distortion, and the inner (R$<6$ kpc) LMC disk warps are the most promising probe of this quadrupole. For the first time, we construct a BFE to quantify the LMC's disk perturbations resulting from the SMC and halo torques. We find that the LMC's disk is significantly perturbed prior to the Clouds' Milky Way infall, possessing warps with a mean vertical extent of $\sim1$ kpc. Finally, we apply multi-channel singular spectral analysis (mSSA) to the time-series of the disk BFE coefficients, halo quadrupole, and the LMC-SMC orbit. mSSA successfully separates the temporal evolution of the LMC warps into components correlated with the halo versus the SMC. Our framework identifies correlated evolution between the LMC's halo distortions and the LMC's disk perturbations, enabling the Clouds to be a precision laboratory for DM physics.
