论文标题
Hermeian Haloes:过去有两个相互作用的极端物体
Hermeian haloes: extreme objects with two interactions in the past
论文作者
论文摘要
基于本地群体的数值模型的最新研究预测了过去曾访问过银河系和M31的田间光环和星系的存在,称为Hermeian Haloes。我们使用来自Multidark Suite的两个高分辨率暗物质n体模拟的两个高分辨率暗物质模拟将该分析扩展到本地组。我们将Hermeian Haloes定义为现场光环,过去与其他两个更大的田野光环有着密切的相互作用,称为目标。我们发现,与仅经历过一次相互作用的著名的后挡光晕相比,赫尔摩式光环是过去与互动相比的田野光环的一个极端例子。与后挡板相比,爱马仕人具有更集中的密度曲线,并且倾向于占据更大的区域。相对于目标光环,它们也具有较高的速度,并且相对于1〜 $ H^{ - 1} \; \ Mathrm {MPC} $。在模拟中的每个光环(如果分辨率足够)中可以找到Hermeian的光环,并占田间光环总数的0.4%至2.3%(对于比$ 10^{10} \; H^{ - h^{ - 1} { - 1} \; \; \ m m _ {m _ _ _ {m _ {m _ { H^{ - 1} \; \ Mathrm {M _ {\ odot}} $)在过度密度区域中增加到10%。它们倾向于分布在连接目标的线路附近,这可能有助于识别观测值中的Hermeian光环。我们还确定了模拟中的本地组类似物,发现如果两个主要光环之间的距离低于1〜 $ h^{ - 1} \; \ mathrm {mpc} $,则大约有四分之一(49个)包含HERMEIAN光环。
Recent studies based on numerical models of the Local Group predict the existence of field haloes and galaxies that have visited both the Milky Way and M31 in the past, called Hermeian haloes. We extend this analysis beyond the Local Group using two high-resolution dark matter-only N-body simulations from the MultiDark suite. We define Hermeian haloes as field haloes which had close interactions with two other more massive field haloes in the past, called targets. We find that Hermeian haloes are a more extreme example of field haloes with interactions in the past than the well-known backsplash haloes that experienced only one interaction. Compared to backsplashers, Hermeians have more concentrated density profiles and tend to occupy more overdense regions. They also have higher velocities relative to their target haloes and relative to their neighbours within 1~$h^{-1}\; \mathrm{Mpc}$. Hermeian haloes can be found around every halo in the simulation (if the resolution is sufficient) and make up 0.4 to 2.3 per cent of the total number of field haloes (for haloes more massive than $10^{10}\; h^{-1}\;\mathrm{M_{\odot}}$ and $3.3 \times 10^{7}\; h^{-1}\;\mathrm{M_{\odot}}$, respectively), increasing to 10 per cent in overdense regions. They tend to be distributed close to the line connecting their targets, which may help to identify Hermeian haloes in observations. We also identify Local Group analogues in the simulation and find that about one-third (15 out of 49) of them contain Hermeian haloes if the distance between the two main haloes is below 1~$h^{-1} \;\mathrm{Mpc}$.