标题： 暗物质子结构统计：II. 模型与模拟结果的比较 显示英文标题

标题： Statistics of Dark Matter Substructure: II. Comparison of Model with Simulation Results

摘要： 我们比较了不同模拟中使用不同子晕探测器得到的子晕质量函数和速度函数，以及与Jiang & van den Bosch (2014)的新半解析模型的预测结果进行比较。 我们发现，使用不同子晕探测器得到的子晕质量函数（SHMFs）在低质量端大约20%的范围内相互一致，但在高质量端，仅基于配置空间密度识别子晕的探测器大大低估了子晕的数量，超过一个数量级。 这些问题在子晕速度函数（SHVFs）中要严重得多，这表明问题出在将质量分配给子晕上，而不是检测子晕本身。 总体而言，半解析模型的预测与使用六维相空间信息的更先进的子晕探测器得到的模拟结果非常一致。 特别是，该模型准确地再现了子晕质量函数和速度函数的斜率以及与宿主质量相关的归一化值。 我们发现SHMFs和SHVFs的幂律斜率分别为0.82和2.6，明显比文献中一些研究声称的要平缓。 显示英文摘要

摘要： We compare subhalo mass and velocity functions obtained from different simulations with different subhalo finders among each other, and with predictions from the new semi-analytical model of Jiang & van den Bosch (2014). We find that subhalo mass functions (SHMFs) obtained using different subhalo finders agree with each other at the level of ~ 20 percent, but only at the low mass end. At the massive end, subhalo finders that identify subhaloes based purely on density in configuration space dramatically underpredict the subhalo abundances by more than an order of magnitude. These problems are much less severe for subhalo velocity functions (SHVFs), indicating that they arise from issues related to assigning masses to the subhaloes, rather than from detecting them. Overall the predictions from the semi-analytical model are in excellent agreement with simulation results obtained using the more advanced subhalo finders that use information in six dimensional phase-space. In particular, the model accurately reproduces the slope and host-mass-dependent normalization of both the subhalo mass and velocity functions. We find that the SHMFs and SHVFs have power-law slopes of 0.82 and 2.6, respectively, significantly shallower than what has been claimed in several studies in the literature.