AI 中文总结
该研究通过VST ATLAS星系、LRG和QSO聚类及与ACT CMB透镜图交叉关联分析，用ΛCDM Halofit模型在不同尺度估计偏差和σ8，通过HOD模型拟合晕质量分布，发现QSO相关异常，为星系聚类和质量分布研究提供新认知。
AI 中文摘要
我们展示了VST ATLAS星系、大质量红移星系（LRG）和类星体（QSO）聚类的角关联和功率谱分析，以及它们与ACT DR6 CMB引力透镜图的交叉关联，ACT DR6的分辨率比普朗克DR3高约3倍。首先在线性尺度上使用ΛCDM Halofit模型，通过三维功率谱的比值估计星系、LRG和QSO的偏差b，从而得到质量聚类幅度σ8。对于星系和LRG，结果与ΛCDM预测一致，但QSO的σ8显著低于预期，其引力增长率比ΛCDM预测的快。在较小的非线性尺度上，晕占据分布（HOD）模型拟合表明z≈0.15的星系晕质量分布较宽，LRG和QSO的较窄，QSO的有效质量比预期高约10倍。此外，LRG和QSO的HOD模型能一致拟合相关量，而z≈0.15的星系除非假设反偏差否则不行。这支持了之前QSO透镜分析中在r<5h−1Mpc处发现反偏差的结果。我们认为HOD+NFW晕模型可能很好地描述LRG质量分布和聚类，但在中间尺度上，主要星系群体（和QSO）可能遵循替代的层次聚类模型，其中星系比晕模型更紧密地追踪质量。
英文摘要
We present angular correlation and power spectral analyses of the clustering of VST ATLAS galaxies, LRGs and QSOs and their cross-correlations with the ACT DR6 CMB lensing map with its $\approx3\times$ higher resolution than Planck DR3. We first use $Λ$CDM Halofit models at linear scales to estimate galaxy, LRG and QSO bias, $b$, from the ratio of the 3-D power spectra, $b= P_{gg}/P_{gK}$ and hence the mass clustering amplitudes, $σ_8$. For galaxies we find $b_G(z=0.15)=1.22\pm0.07$, $σ_8(z=0)=0.71\pm0.06$ and for LRGs $b_{LRG}(z=0.26)=2.76\pm0.11$, $σ_8(z=0)=0.63\pm0.15$, both consistent with $Λ$CDM predictions. But for QSOs, we estimate a bias of $b_Q(z=1.7)=4.44\pm0.24$ and $σ_8(z=0)=0.49\pm0.06$, the latter significantly lower than expected for $Λ$CDM and leads to an observed $0.15<z<1.7$ gravitational growth rate faster than predicted for $Λ$CDM. At smaller non-linear scales, HOD model fits imply a broad halo mass distribution for $z\approx0.15$ galaxies but much narrower mass distributions for LRGs and QSOs. More surprisingly, the HOD fit for QSOs implies $M_{eff}=5\times10^{14}M_\odot$, $\approx10\times$ higher than expected. Finally, while the LRG and QSO HOD models fit $w_{gg}$ and $w_{gK}$ consistently, the same is not true for the $z\approx0.15$ galaxies unless we hypothesise anti-bias with $b_G\approx0.55$. This result supports previous QSO lensing analyses that also found anti-bias at $r<5$h$^{-1}$Mpc. We suggest that while HOD + NFW halo models may well describe LRG mass profiles and clustering, at intermediate scales the dominant galaxy population (and QSOs) may follow the alternative hierarchical clustering model of Peebles(1974) where galaxies trace the mass more closely than in a halo model.
Comments16 pages, 16 figures, submitted to MNRAS. Minus sign typos in Section 8 now fixed
