Suppressing Linear Power on Dwarf Galaxy Halo Scales
Suppressing Linear Power on Dwarf Galaxy Halo Scales
复制标题
抑制矮星系光环尺度上的线性功率
DOI：
10.1086/309273
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
R. Croft
中科院分区：
文献类型：
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作者：
M. White;R. Croft
最近，有人提出，银河系周围缺乏小晕的原因是暴胀导致的波动的原始功率谱发生了变化。这样的修改预计将改变结构的形成从自下而上到自上而下的规模附近的短尺度功率已被抑制。利用宇宙学模拟，我们研究了这种修改的初始功率谱的影响。虽然晕多重性函数主要取决于线性理论功率谱，但大多数其他功率探测器对非线性功率谱更敏感。当大尺度结构非线性时，它们的崩溃在功率谱中再生一个“尾巴”，掩盖了对原始功率谱的小尺度修改，除了在非常高的z。即使是Lyα森林的小尺度（k > 2 h Mpc-1）聚类也会受到这个过程的影响，因此，具有足够功率抑制的冷暗物质（CDM）模型可以将1010 M的晕的数量减少到大约5倍，从而给出类似的Lyα森林功率谱结果。我们的结论是，其他观测更直接地依赖于坍缩天体的数密度，如阻尼Lyα系统的数量或再电离的红移，可能提供这些模型的最敏感的测试。
Recently, it has been suggested that the dearth of small halos around the Milky Way arises because of a modification of the primordial power spectrum of fluctuations from inflation. Such modifications would be expected to alter the formation of structure from bottom-up to top-down on scales near where the short-scale power has been suppressed. Using cosmological simulations, we study the effects of such a modification of the initial power spectrum. While the halo multiplicity function depends primarily on the linear-theory power spectrum, most other probes of power are more sensitive to the nonlinear power spectrum. Collapse of large-scale structures as they go nonlinear regenerates a "tail" in the power spectrum, masking small-scale modifications to the primordial power spectrum except at very high z. Even the small-scale (k > 2 h Mpc-1) clustering of the Lyα forest is affected by this process, so that cold dark matter (CDM) models with sufficient power suppression to reduce the number of 1010 M☉ halos by a factor of ~5 give similar Lyα forest power spectrum results. We conclude that other observations that depend more directly on the number density of collapsed objects, such as the number of damped Lyα systems or the redshift of reionization, may provide the most sensitive tests of these models.