AI 中文总结
本研究首次对近红外EBL各向异性开展层析交叉关联分析，发现低红移LSS是近红外EBL波动的重要贡献源，为后续相关交叉关联研究奠定基础。
AI 中文摘要
我们对近红外河外背景光（EBL）各向异性开展了首次层析分析，将CIBER 1.1和1.8μm成像仪数据与DESI Legacy Survey DR8及Hyper-Suprime-Cam Ultra-Deep Survey的测光星系星表进行交叉关联。我们测量得到的交叉功率在ℓ<2000的尺度上显著高于积分星系光（IGL）模型的预期，且集中在低红移（z≲0.6）区域。星系团成员星系及相关结构贡献了15%-20%的大角尺度交叉功率，表明星系群和星系尺度的暗晕是该信号的主要来源。通过参数化暗晕模型分解，我们在交叉功率中高显著性地探测到了双暗晕和单暗晕成团信号，其振幅在z=0-1范围内平滑下降。DESI-LS与更深的HSC星表所推得的单暗晕交叉功率振幅相近，这暗示低红移EBL波动由含卫星星系和/或弥散星系内光（IHL）的低质量暗晕贡献放大的场景。将我们的双暗晕拟合转换为b_I×dI/dz的估计值后，发现标准IGL预测低估了我们的测量结果，即便假设强度偏置高达3（类似大型SZ星系团的偏置），仍表明需要更高的dI/dz来协调观测差异。最后，我们发现z<1的关联大尺度结构（LSS）构成了此前研究中报道的CIBER自功率的重要部分。这些结果表明低红移LSS是近红外EBL波动测量中重要且此前未被充分认识的贡献源，为利用CIBER-2、SPHEREx及多种LSS示踪剂开展交叉关联科学研究奠定了基础。
英文摘要
We perform the first tomographic analysis of near-IR extragalactic background light (EBL) anisotropies, cross-correlating CIBER 1.1 and 1.8 $μ$m imager data with photometric galaxy catalogs from DESI Legacy Survey DR8 and Hyper-Suprime-Cam Ultra-Deep Survey. We measure significantly higher cross-power than expectations from an integrated galaxy light (IGL) model on scales $\ell < 2000$, concentrated at low redshift ($z\lesssim 0.6$). Cluster member galaxies and associated structure account for 15-20\% of the large-angle cross-power, indicating that group- and galaxy-scale halos contribute the bulk of the signal. Through a parametric halo model decomposition, we detect two-halo and one-halo clustering in cross-power at high significance, with amplitudes that decline smoothly across $z=0{-}1$. The inferred one-halo cross-power is of similar amplitude between DESI-LS and the deeper HSC catalog, implying a scenario in which low-redshift EBL fluctuations are amplified by contributions from lower-mass halos with satellites and/or diffuse intra-halo light (IHL). Converting our two-halo fits into estimates of $b_I \times dI/dz$, we find that standard IGL predictions underestimate our measurements, even when assuming an intensity bias as high as 3, similar to that of large SZ clusters, suggesting that a higher $dI/dz$ is required to reconcile observed discrepancies. Lastly, we find that correlated large-scale structure (LSS) at $z<1$ accounts for a substantial fraction of the CIBER auto-power reported in earlier work. These results identify low-redshift LSS as a significant and previously unappreciated contributor to near-IR EBL fluctuation measurements, setting the stage for cross-correlation science with CIBER-2, SPHEREx and a variety of LSS tracers.
Comments29+12 pages, 12+10 figures, 3 tables. To be submitted to JCAP
