新采样活动星系核（AGN）样本中的偶极各向异性：仍与宇宙微波背景（CMB）偶极存在张力
Dipole Anisotropy in Newly Sampled AGN Population: Still in Tension with CMB Dipole
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中文总结 AI 辅助
该研究通过改进准则从WISE星表采样新AGN样本，发现其数计数偶极各向异性幅度为纯运动学起源的2.5倍、置信度5.3σ，方向与CMB偶极偏差约3σ，仍与CMB偶极存在张力并探讨相关宇宙学意义。
中文摘要 AI 辅助
我们重新分析了全天巡天数据——广域红外巡天探测器（WISE）星表，采用改进的星系选择准则，以研究星系数计数中的偶极各向异性与运动学CMB偶极各向异性之间的不一致性。我们应用一套由流量阈值和多个色指数阈值组成的活动星系核（AGN）选择准则，并针对光谱能量分布偏离纯幂律形式的测光巡天样本，对原始的Ellis & Baldwin（1984）形式体系进行了适当调整。我们发现，从WISE星表中采样的新AGN仍存在异常的数计数偶极各向异性，其幅度为纯运动学起源幅度的约2.5倍，置信度达5.3σ。我们还发现，WISE-AGN偶极的方向与CMB偶极方向的偏差约为3σ。我们讨论了其可能的宇宙学意义：近邻宇宙的非线性以及物质静止参考系与CMB静止参考系的不匹配。
英文摘要
We revisit the all-sky survey data, the Wide-field Infrared Survey Explorer (WISE) catalog, with an improved galaxy-selection criterion to investigate the inconsistency between the dipole anisotropy in the galaxy number count and the kinematic CMB dipole anisotropy. We apply a set of active galactic nuclei (AGN) selection criteria composed of a flux cut and multiple color cuts, and formulate an appropriate adaptation of the original Ellis & Baldwin (1984) formalism for our photometric survey samples whose spectral energy distributions deviate from a pure power-law form. We find that the newly sampled AGNs from the WISE catalog still bears an anomalous number-count dipole anisotropy, whose amplitude is ~ 2.5 times as large as that of the purely kinematic origin at a 5.3 sigma confidence level. We also find that the direction of our WISE-AGN dipole is ~ 3 sigma away from that of the CMB dipole. We discuss its possible cosmological implications: nonlinearity of the nearby universe and mismatch of matter-rest frame and the CMB-rest frame.
