Detection of the LMC-induced sloshing of the Galactic halo
Detection of the LMC-induced sloshing of the Galactic halo
复制标题
检测 LMC 引起的银河晕晃动
DOI：
10.1093/mnras/stab1828
复制
发表时间：
2021
影响因子：
4.8
通讯作者：
Zhao Gang
中科院分区：
文献类型：
--
作者：
Erkal Denis;Deason Alis J.;Belokurov Vasily;Xue Xiang-Xiang;Koposov Sergey E.;Bird Sarah A.;Liu Chao;Simion Iulia T.;Yang Chengqun;Zhang Lan;Zhao Gang
A wealth of recent studies have shown that the LMC is likely massive, with a halo mass >1011M⊙. One consequence of having such a nearby and massive neighbour is that the inner Milky Way is expected to be accelerated with respect to our Galaxy’s outskirts (beyond ∼30 kpc). In this work, we compile a sample of ∼500 stars with radial velocities in the distant stellar halo,rGC> 50 kpc, to test this hypothesis. These stars span a large fraction of the sky and thus give a global view of the stellar halo. We find that stars in the Southern hemisphere are on average blueshifted, while stars in the North are redshifted, consistent with the expected, mostly downwards acceleration of the inner halo due to the LMC. We compare these results with simulations and find the signal is consistent with the infall of a 1.5 × 1011M⊙LMC. We cross-match our stellar sample withGaiaDR2 and find that the mean proper motions are not yet precise enough to discern the LMC’s effect. Our results show that the Milky Way is significantly out of equilibrium and that the LMC has a substantial effect on our Galaxy.
