发表机构
Swinburne University of Technology; ARC Centre of Excellence for Dark Matter Particle Physics (CDM)（斯威本科技大学; 暗物质粒子物理卓越研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用千年模拟，通过成团性测量恢复稀有暗晕的特征质量，发现中位偏差0.103 dex，并量化了样本大小和参考群体误差的影响。
AI 中文摘要
我们利用千年模拟中的暗物质晕（其中真实质量已知）来测量仅从成团性中恢复稀有、大质量群体的特征暗晕质量的准确度。在$0 \leq z \leq 5.29$的六个红移处，将包含25至10000个暗晕的大质量样本与包含5000至50000个暗晕的场参考样本进行互相关。在$r = 8\\,h^{-1}\\,\mathrm{Mpc}$处测量偏置，并反演以返回特征质量，我们将其与直接从模拟中测量的平均对数暗晕质量进行比较。在192种配置中，特征质量恢复的中位绝对偏差为$0.103$ dex。我们表明：（i）准确度仅微弱依赖于稀有天体的数量，而不确定性从25个天体时的$\pm 0.71$ dex下降到10000个天体时的$\pm 0.08$ dex；（ii）扩大最小样本的收益最大，从25个增加到50个天体使不确定性减少约三分之一，而从5000个增加到10000个仅减少十分之一；（iii）参考群体自身带有误差，该误差会相干地传播到针对它的每次互相关中，并且不会因观测更多稀有天体而减小。使用暗晕而非星系将成团性测量与星系-暗晕连接隔离开来，在引入特定于群体的复杂性之前提供了一个基准。对于最佳配置，偏置-质量关系校准所贡献的不确定性（约$0.07$ dex）已经与测量本身的不确定性相当。
英文摘要
We measure how accurately the characteristic halo mass of a rare, massive population can be recovered from clustering alone, using dark matter haloes in the Millennium simulation, where the true masses are known. Massive samples of 25 to 10000 haloes are cross-correlated against field reference samples of 5000 to 50000 haloes at six redshifts over $0 \leq z \leq 5.29$. The bias is measured at $r = 8\,h^{-1}\,\mathrm{Mpc}$ and inverted to return a characteristic mass, which we compare with the mean logarithmic halo mass measured directly from the simulation. Across 192 configurations the characteristic mass is recovered with a median absolute offset of $0.103$ dex. We show that (i) accuracy depends only weakly on the number of rare objects while the uncertainty falls from $\pm 0.71$ dex at 25 objects to $\pm 0.08$ dex at 10000; (ii) enlarging the smallest samples gives the greatest return, with a doubling from 25 to 50 objects reducing the uncertainty by about a third, against a tenth from 5000 to 10000; and (iii) the reference population carries an error of its own, which propagates coherently into every cross-correlation measured against it and is not reduced by observing more rare objects. Working with haloes rather than galaxies isolates the clustering measurement from the galaxy--halo connection, providing a benchmark before population-specific complications are introduced. For the best configurations, the uncertainty contributed by the calibration of the bias--mass relation, at $\sim 0.07$ dex, already matches that of the measurement itself.
Comments15 pages, 7 figures, 5 tables; Submitted to MNRAS
