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arXiv 2201.09540astro-ph.COastro-ph.GA
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大尺度暗条周围晕轨道及其质量演化的跟踪

Tracking Halo Orbits and Their Mass Evolution around Large-scale Filaments

Hannah Jhee, Hyunmi Song, Rory Smith, Jihye Shin, Inkyu Park, Clotilde Laigle

摘要:

我们利用相空间分析的方法,利用只考虑暗物质的宇宙学模拟,研究了大尺度暗物质驱动的晕的动力学和质量演化。由于预计有不可忽略的星系数量会通过大尺度细丝落入星系团环境,因此跟踪晕如何围绕大尺度细丝移动可以提供对星系团星系演化的更全面的看法。晕围绕暗条作轨道运动,在由晕相对暗条的垂直距离和速度分量组成的相空间中表现为特定的轨道。这些相空间轨迹可以根据其当前状态由三种情况表示。我们用晕的初始位置和速度、最大速度、形成时间和首次穿越时间来描述轨道,发现它们之间是相互关联的。这些相关性在大尺度结构形成的背景下得到了很好的解释。晕的质量演化和动力学性质似乎受到暗条密度的影响,这可以从以下事实中得到证明:在密度较大的暗条周围的晕更容易失去质量并被束缚在大尺度的暗条中。最后,我们再现了观察中发现的长丝周围的质量偏析趋势。这是因为形成较早的晕更早地到达丝状体,并且在那里更有效地生长。我们还发现,动态摩擦有助于保持这种分离趋势。

英文摘要:

We have explored the dynamical and mass evolution of halos driven by large-scale filaments using a dark matter-only cosmological simulation with the help of a phase-space analysis. Since a non-negligible number of galaxies is expected to fall into the cluster environment through large-scale filaments, tracking how halos move around large-scale filaments can provide a more comprehensive view on the evolution of cluster galaxies. Halos exhibit orbital motions around filaments, which emerge as specific trajectories in a phase space composed of halos' perpendicular distance and velocity component with respect to filaments. These phase-space trajectories can be represented by three cases according to their current states. We parameterize the trajectories with halos' initial position and velocity, maximum velocity, formation time, and time since first crossing, which are found to be correlated with each other. These correlations are explained well in the context of the large-scale structure formation. The mass evolution and dynamical properties of halos seem to be affected by the density of filaments, which can be shown from the fact that halos around denser filaments are more likely to lose their mass and be bound within large-scale filaments. Finally we reproduce the mass segregation trend around filaments found in observations. It is resulted because halos that formed earlier arrived filaments earlier, and grew efficiently there being more massive. We also found that dynamical friction helps to retain this segregation trend.

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。

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