The effect of the deforming dark matter haloes of the Milky Way and the Large Magellanic Cloud on the Orphan-Chenab stream
The effect of the deforming dark matter haloes of the Milky Way and the Large Magellanic Cloud on the Orphan-Chenab stream
复制标题
银河系和大麦哲伦星云变形暗物质晕对孤儿-奇纳布流的影响
DOI：
10.1093/mnras/stac3108
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发表时间：
2022
影响因子：
5.6
通讯作者：
T. Hilmi
中科院分区：
文献类型：
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作者：
Sophia Lilleengen;M. Petersen;D. Erkal;J. Peñarrubia;Sergey E. Koposov;Ting S. Li;L. Cullinane;A. Ji;K. Kuehn;G. Lewis;D. Mackey;A. Pace;N. Shipp;D. Zucker;J. Bland;T. Hilmi
最近的研究表明，大麦哲伦星云（LMC）对银河系的星晕和星流有着重要的影响。在这里，我们将探讨银河系和大麦哲伦星系的暗物质的变形如何晕出一个不规则的恒星流，以及这些效应是否是可观测的。特别是，我们专注于孤儿Chenab（OC）流，特别接近LMC和跨越银河系的晕的大部分。我们代表银河系LMC系统使用基函数展开，捕捉他们的演变？- 身体模拟。我们介绍了这个系统的性质，例如每个星系的密度和力场的演化。OC流是在这种随时间变化的变形势中演化的，我们研究了银河系和LMC的各种时刻的影响。我们发现模拟的OC流强烈地受到银河系和LMC变形的影响，并且这种影响远远大于当前的观测误差。特别是，银河系偶极子对流的影响最大，其次是LMC的四极子和LMC的四极子。探测到这些效应将证实无碰撞冷暗物质的关键预测，并将是对替代暗物质和替代引力模型的有力测试。
It has recently been shown that the Large Magellanic Cloud (LMC) has a substantial effect on the Milky Way’s stellar halo and stellar streams. Here, we explore how deformations of the Milky Way and LMC’s dark matter haloes affect stellar streams, and whether these effects are observable. In particular, we focus on the Orphan-Chenab (OC) stream which passes particularly close to the LMC and spans a large portion of the Milky Way’s halo. We represent the Milky Way–LMC system using basis function expansions that capture their evolution in an ? -body simulation. We present the properties of this system, such as the evolution of the densities and force fields of each galaxy. The OC stream is evolved in this time-dependent, deforming potential, and we investigate the effects of the various moments of the Milky Way and the LMC. We find that the simulated OC stream is strongly influenced by the deformations of both the Milky Way and the LMC and that this effect is much larger than current observational errors. In particular, the Milky Way dipole has the biggest impact on the stream, followed by the evolution of the LMC’s monopole, and the LMC’s quadrupole. Detecting these effects would confirm a key prediction of collisionless, cold dark matter, and would be a powerful test of alternative dark matter and alternative gravity models.