COSMIC REIONIZATION ON COMPUTERS. III. THE CLUMPING FACTOR
COSMIC REIONIZATION ON COMPUTERS. III. THE CLUMPING FACTOR
复制标题
计算机上的宇宙再电离。
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
N. Gnedin
中科院分区：
文献类型：
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作者：
A. Kaurov;N. Gnedin
我们使用完全自洽的数值模拟宇宙再电离，完成下的宇宙再电离计算机项目，探索如何以及在电离星系际介质（IGM）的重组可以量化的有效的“聚集因子”。模拟中的密度分布（大概也是真实的宇宙中的密度分布）是高度不均匀的，在空间中的变化或多或少是平滑的。然而，即使在高度复杂和动态的环境中，IGM的概念仍然相当明确;最大的模糊性来自星系周围的非维里化区域，这些区域由于辐射场的局部增强而过度电离（“邻近区”）。这种模糊性排除了计算IGM聚集因子以优于约20%。我们还讨论了一个“局部聚集因子”，定义在一个特定的空间尺度，并量化其分散在一个给定的规模和它的变化作为规模的函数。
We use fully self-consistent numerical simulations of cosmic reionization, completed under the Cosmic Reionization On Computers project, to explore how well the recombinations in the ionized intergalactic medium (IGM) can be quantified by the effective “clumping factor.” The density distribution in the simulations (and, presumably, in a real universe) is highly inhomogeneous and more-or-less smoothly varying in space. However, even in highly complex and dynamic environments, the concept of the IGM remains reasonably well-defined; the largest ambiguity comes from the unvirialized regions around galaxies that are over-ionized by the local enhancement in the radiation field (“proximity zones”). That ambiguity precludes computing the IGM clumping factor to better than about 20%. We also discuss a “local clumping factor,” defined over a particular spatial scale, and quantify its scatter on a given scale and its variation as a function of scale.