The Bound Mass of Substructures in Dark Matter Halos
The Bound Mass of Substructures in Dark Matter Halos
复制标题
暗物质晕中子结构的束缚质量
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
P. Bode
中科院分区：
文献类型：
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作者：
L. Shaw;J. Weller;J. Ostriker;P. Bode
我们提出了一个新的定义subhalos在无耗散暗物质N体模拟的基础上，其动态约束成分的相干识别。而以前的方法确定的能量绑定组件的subhalo忽略了所有剩余的粒子在晕（那些不几何或动态相关的subhalo）的贡献，我们的方法允许所有的力量，内部和外部，施加在subhalo。我们证明，在不同的时间步长使用模拟的输出，我们的新方法是更准确地识别subhalo的束缚质量。然后，我们将我们的新方法与以前采用的方法进行比较，通过将每个方法应用于从高分辨率宇宙学模拟中提取的1838个维里化晕的样本来识别subhalos。我们发现，在每种情况下的subhalo分布是相似的，并在subhalo的结合能的增加，包括所有的粒子位于它几乎完全平衡的损失，由于外力; subhalos的质量分数的净增加约为10%，和额外的子结构往往驻留在系统的内部。最后，我们比较的subhalo人口的晕subsubhalo人口的subhalo，发现这两个分布是相似的。这是一个新的和有趣的结果，表明在集群质量晕的层次结构的自相似性。
We present a new definition of subhalos in dissipationless dark matter N-body simulations, based on the coherent identification of their dynamically bound constituents. Whereas previous methods of determining the energetically bound components of a subhalo ignored the contribution of all the remaining particles in the halo (those not geometrically or dynamically associated with the subhalo), our method allows for all the forces, both internal and external, exerted on the subhalo. We demonstrate, using the output of a simulation at different time steps, that our new method is more accurate at identifying the bound mass of a subhalo. We then compare our new method to previously adopted means of identifying subhalos by applying each to a sample of 1838 virialized halos extracted from a high-resolution cosmological simulation. We find that the subhalo distributions are similar in each case, and that the increase in the binding energy of a subhalo from including all the particles located within it is almost entirely balanced by the losses due to the external forces; the net increase in the mass fraction of subhalos is roughly 10%, and the extra substructures tend to reside in the inner parts of the system. Finally, we compare the subhalo populations of halos to the subsubhalo populations of subhalos, finding the two distributions to be similar. This is a new and interesting result, suggesting a self-similarity in the hierarchy substructures within cluster mass halos.