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arXiv 1811.09487astro-ph.CO
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与潮汐力矩理论的偏差:环境对晕angular momentum生长的依赖性

Deviations from tidal torque theory: environment dependences on halo angular momentum growth

Pablo López, Manuel E. Merchán, Dante J. Paz

摘要:

潮汐力矩理论(TTT)将角动量的起源和演化与暗物质(DM)晕形成的环境联系起来。由后期非线性引入的偏差通常被认为是模型中的噪声。在这项工作中,我们分析了宇宙学模拟寻找这些偏差的系统学,发现DM晕的分类根据其角动量增长的结果在不同的内部对齐,自旋参数分布和组装历史的样品。基于这种分类,我们得到,低质量的晕是嵌入在密集的环境中,如果他们已经获得的角动量低于TTT的预期(L晕),而在高质量的增强集群通常与较高的角动量增长(W晕)。此外,我们发现,低质量的信号有一个弱的方向依赖性,而高质量的信号是完全由于垂直于角动量的结构。最后,我们研究了晕周围的物质分布的各向异性作为其质量的函数。我们发现W(L)晕的角动量方向在统计上保持垂直(平行)周围的结构在整个质量范围$11<\mathrm{log}(M/h^{-1}\mathrm{M}_{\odot})<14$,而TTT后的晕显示出“自旋翻转”的质量与以前报道的值($\sim 5 \times 10^{12}$ $h^{-1}\mathrm{M}_\odot$)一致。因此,无论偏离样品的自旋翻转质量是高度移位还是直接未定义,我们的结果都表明这与晕的角动量增长显著相关。

英文摘要:

The tidal torque theory (TTT) relates the origin and evolution of angular momentum with the environment in which dark matter (DM) haloes form. The deviations introduced by late non-linearities are commonly thought as noise in the model. In this work, we analyze a cosmological simulation looking for systematics on these deviations, finding that the classification of DM haloes according to their angular momentum growth results in samples with different internal alignment, spin parameter distribution and assembly history. Based on this classification, we obtain that low mass haloes are embedded in denser environments if they have acquired angular momentum below the TTT expectations (L haloes), whereas at high masses enhanced clustering is typically associated with higher angular momentum growths (W haloes). Additionally, we find that the low mass signal has a weak dependence on the direction, whereas the high mass signal is entirely due to the structure perpendicular to the angular momentum. Finally, we study the anisotropy of the matter distribution around haloes as a function of their mass. We find that the angular momentum direction of W (L) haloes remains statistically perpendicular (parallel) to the surrounding structure across the mass range $11<\mathrm{log}(M/h^{-1}\mathrm{M}_{\odot})<14$, whereas haloes following TTT show a "spin flip" mass consistent with previously reported values ($\sim 5 \times 10^{12}$ $h^{-1}\mathrm{M}_\odot$). Hence, whether the spin flip mass of the deviated samples is highly shifted or straightly undefined, our results indicate that is remarkably connected to the haloes angular momentum growth.

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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