论文标题
热SZ效应对Planck CMB镜头与SDSS星系密度场之间互相关的影响
Impact of thermal SZ effect on cross-correlations between Planck CMB lensing and SDSS galaxy density fields
论文作者
论文摘要
宇宙微波背景中的星系簇（CMB）映射的热量Sunyaev-Zeldovich（TSZ）效应的残留前景污染构图繁殖到重建的CMB镜头场中，从而偏向CMB透镜和大型结构（LSSS）之间的固有交叉相关性。通过堆叠分析，我们表明残留的TSZ污染会导致簇中心部分的透镜收敛增长，并减少集群郊区的透镜收敛性。我们通过交叉动力频谱计算量化了残留TSZ污染对Planck 2018 CMB镜头收敛图与SDSS-IV星系密度数据之间互相关的影响。与Planck 2018 TSZ删除率图相比，我们使用TSZ污染的Smica镜头图的分析测量了$ \ sim2.5 \％$ $ \％$负偏见$ \ ell \ ell \ ellysim 500 $，并过渡到$ \ sim9 \ sim9 \％$ \％$ \％$ \ el \ g g g g g g g gtry \ g g gtries termim \ g g gtries termim pasterim pasterim pasterim pasterim \ g g gtries。这种TSZ诱导的伪造互相关的形状。 Planck CMB数据中的TSZ引起的镜头收敛场被检测到$ \ ell \ ell \ lyssim 500 $，$ \ ell \ ell \ ell \ ell \ gtrsim1500 $，$ \ ell \ ell \ lyssim 500 $，$ 14。$14.8σ$检测。我们还表明，在CMB数据中掩盖了星系簇不足以消除伪造的镜头信号，但仍检测到具有5.5σ$ $5.5σ$意义的不可忽略的偏差，这对于与星系密度场的交叉相关性。我们的结果强调，在组件分离阶段将CMB图的TSZ效应进行分解是多么重要，并采用无TSZ的CMB镜头图，以与LSS数据进行互相关。
Residual foreground contamination by thermal Sunyaev-Zeldovich (tSZ) effect from galaxy clusters in cosmic microwave background (CMB) maps propagates into the reconstructed CMB lensing field, and thus biases the intrinsic cross-correlation between CMB lensing and large-scale structure (LSS). Through stacking analysis, we show that residual tSZ contamination causes an increment of lensing convergence in the central part of the clusters and a decrement of lensing convergence in the cluster outskirts. We quantify the impact of residual tSZ contamination on cross-correlations between the Planck 2018 CMB lensing convergence maps and the SDSS-IV galaxy density data through cross-power spectrum computation. In contrast with the Planck 2018 tSZ-deprojected SMICA lensing map, our analysis using the tSZ-contaminated SMICA lensing map measures a $\sim2.5\%$ negative bias at multipoles $\ell\lesssim 500$ and transits to a $\sim9\%$ positive bias at $\ell\gtrsim1500$, which validates earlier theoretical predictions of the overall shape of such tSZ-induced spurious cross-correlation. The tSZ-induced lensing convergence field in Planck CMB data is detected with more than $1σ$ significance at $\ell\lesssim 500$ and more than $14σ$ significance at $\ell\gtrsim1500$, yielding an overall $14.8σ$ detection. We also show that masking galaxy clusters in CMB data is not sufficient to eliminate the spurious lensing signal, still detecting a non-negligible bias with $5.5σ$ significance on cross-correlations with galaxy density fields. Our results emphasize how essential it is to deproject the tSZ effect from CMB maps at the component separation stage and adopt tSZ-free CMB lensing maps for cross-correlations with LSS data.
