Title: A Measurement of the Galaxy Group-Thermal Sunyaev-Zel'dovich Effect Cross-Correlation Function Show Chinese title

Title: 星系团-热太阳泽尔多维奇效应交叉关联函数的测量

Abstract: Stacking cosmic microwave background (CMB) maps around known galaxy clusters and groups provides a powerful probe of the distribution of hot gas in these systems via the Sunyaev-Zel'dovich (SZ) effect. A stacking analysis allows one to detect the average SZ signal around low mass halos, and to extend measurements out to large scales, which are too faint to detect individually in the SZ or in X-ray emission. In addition, cross correlations between SZ maps and other tracers of large-scale structure (with known redshifts) can be used to extract the redshift-dependence of the SZ background. Motivated by these exciting prospects, we measure the two-point cross-correlation function between a catalog of $\sim 380,000$ galaxy groups (with redshifts spanning $z=0.01-0.2$) from the Sloan Digital Sky Survey (SDSS) and Compton-y parameter maps constructed by the Planck collaboration. We find statistically significant correlations between the group catalog and Compton-y maps in each of six separate mass bins, with estimated halo masses in the range $10^{11.5-15.5} M_\odot/h$. We compare these measurements with halo models of the SZ signal, which describe the stacked measurement in terms of one-halo and two-halo terms. The one-halo term quantifies the average pressure profile around the groups in a mass bin, while the two-halo term describes the contribution of correlated neighboring halos. For the more massive groups we find clear evidence for the one- and two-halo regimes, while groups with mass below $10^{13} M_\odot/h$ are dominated by the two-halo term given the resolution of Planck data. We use the signal in the two-halo regime to determine the bias-weighted electron pressure of the universe: $\langle b P_e \rangle= 1.50 \pm 0.226 \times 10^{-7}$ keV cm$^{-3}$ (1-$\sigma$) at $z\approx 0.15$. Show Chinese abstract

Abstract: 将宇宙微波背景（CMB）地图堆叠在已知的星系团和星系群周围，通过太阳泽尔多维奇（SZ）效应，可以强有力地探测这些系统中热气体的分布。 堆叠分析允许检测低质量暗晕周围的平均SZ信号，并将测量扩展到大尺度，这些尺度在SZ或X射线辐射中单独检测时太弱。 此外，SZ地图与大尺度结构其他示踪物（具有已知红移）之间的交叉相关性可用于提取SZ背景的红移依赖性。 受到这些令人兴奋前景的推动，我们测量了来自斯隆数字巡天（SDSS）的 $\sim 380,000$ 星系群（红移范围为 $z=0.01-0.2$）目录与普朗克合作组构建的康普顿-y参数图之间的两点交叉关联函数。 我们在六个独立的质量箱中发现，星系群目录与康普顿-y图之间存在统计上显著的相关性，估算的暗晕质量范围为 $10^{11.5-15.5} M_\odot/h$。 我们将这些测量结果与描述SZ信号堆叠测量的一晕项和二晕项的暗晕模型进行了比较。 一晕项量化了质量箱内星系群周围的平均压力分布，而二晕项描述了相关邻近暗晕的贡献。 对于较重的星系群，我们发现了明确的一晕和二晕区域的证据，而对于质量低于 $10^{13} M_\odot/h$ 的星系群，由于普朗克数据的分辨率限制，它们主要由二晕项主导。 我们利用双晕区域的信号来确定宇宙的偏倚加权电子压力：在$z\approx 0.15$处为 $\langle b P_e \rangle= 1.50 \pm 0.226 \times 10^{-7}$ keV cm$^{-3}$ (1-$\sigma$)。