We build a model for the density and integrated Sachs-Wolfe (ISW) profile of supervoid and supercluster structures. Our model assumes that fluctuations evolve linearly from an initial Gaussian random field. We find these assumptions capable of describing N-body simulations and simulated ISW maps remarkably well on large scales. We construct an ISW map based on locations of superstructures identified previously in the SDSS Luminous Red Galaxy sample. A matched filter analysis of the cosmic microwave background confirms a signal at the $3.2-σ$ confidence level and estimates the radius of the underlying structures to be $55 \pm 28 ~h^{-1}$Mpc. The amplitude of the signal, however, is $2-σ$ higher than $Λ$CDM predictions.
The imprints of large-scale structures on the Cosmic Microwave Background can be studied via the CMB lensing and Integrated Sachs-Wolfe (ISW) signals. In particular, the stacked ISW signal around supervoids has been claimed in several works to be anomalously high. In this study, we find cluster and void superstructures using four tomographic redshift bins with $0<z<0.8$ from the DESI Legacy Survey, and measure the stacked CMB lensing and ISW signals around them. To compare our measurements with $Λ$CDM model predictions, we construct a mock catalogue with matched galaxy number density and bias,…
The integrated Sachs-Wolfe imprint of extreme structures in the cosmic web probes the dynamical nature of dark energy. Looking through typical cosmic voids, no anomalous signal has been reported. On the contrary, supervoids, associated with large-scale fluctuations in the gravitational potential, have shown potentially disturbing excess signals. In this study, we used the Jubilee ISW simulation to demonstrate how the stacked signal depends on the void definition. We found that large underdensities, with at least $\approx5$ merged sub-voids, show a peculiar ISW imprint shape with central cold s…
The late-time integrated Sachs-Wolfe (ISW) imprint of $R\gtrsim 100~h^{-1}{\rm Mpc}$ super-structures is sourced by evolving large-scale potentials due to a dominant dark energy component in the $Λ$CDM model. The aspect that makes the ISW effect distinctly interesting is the repeated observation of stronger-than-expected imprints from supervoids at $z\lesssim0.9$. Here we analyze the un-probed key redshift range $0.8<z<2.2$ where the ISW signal is expected to fade in $Λ$CDM, due to a weakening dark energy component, and eventually become consistent with zero in the matter dominated epoch. On t…
The largest structures in the cosmic web probe the dynamical nature of dark energy through their integrated Sachs-Wolfe imprints. In the strength of the signal, typical cosmic voids have shown good consistency with expectation $A_{\rm ISW}=ΔT^{\rm data} / ΔT^{\rm theory}=1$, given the substantial cosmic variance. Discordantly, large-scale hills in the gravitational potential, or supervoids, have shown excess signals. In this study, we mapped out 87 new supervoids in the total 5000 deg$^2$ footprint of the Dark Energy Survey at $0.2<z<0.9$ to probe these anomalous claims. We found an excess imp…
The Integrated Sachs-Wolfe Signal from BOSS Super-Structures
宇宙结构通过综合的萨克斯-沃尔夫效应在微波背景辐射上留下印记。我们使用SDSS-III重子声学振荡巡天在红移0.43 < z < 0.65处构造了线性信号的模板图。我们在97%的置信水平下验证了这张图在普朗克CMB温度图上的印记，并与密度-温度互相关测量结果一致。使用这个ISW重建作为模板，我们调查的存在下，ISW源，并进一步研究的Granett-Neyrinck-Szapudi超空和超星系团目录的属性。我们首次对这些结构的三维密度分布进行了研究，并证明它们是重要的结构。模型拟合表明，超空是沿着视线拉长，我们建议，这种特殊的取向可以挑选出来的光度红移空间中的空洞发现算法。我们从公开的空洞和星团星表中测量了普朗克图中的平均温度分布。在试图最大限度地堆叠ISW信号，我们构建了一个新的目录的超级结构的基础上，当地的高峰和低谷的引力势。然而，我们没有发现这些结构和CMB温度之间的显着相关性。
We use data from the DESI Legacy Survey imaging to probe the galaxy density field in tomographic slices covering the redshift range $0<z<0.8$. After careful consideration of completeness corrections and galactic cuts, we obtain a sample of $4.9\times 10^7$ galaxies covering 17 739 deg$^2$. We derive photometric redshifts with precision $σ_z/(1+z)=0.012 - 0.015$, and compare with alternative estimates. Cross-correlation of the tomographic galaxy maps with Planck maps of CMB temperature and lensing convergence probe the growth of structure since $z=0.8$. The signals are compared with a fiducial …
The decay of gravitational potentials in the presence of dark energy leads to an additional, late-time contribution to anisotropies in the cosmic microwave background (CMB) at large angular scales. The imprint of this so-called integrated Sachs-Wolfe (ISW) effect to the CMB angular power spectrum has been detected and studied in detail, but reconstructing its spatial contributions to the CMB $\textit{map}$, which would offer the tantalizing possibility of separating the early- from the late-time contributions to CMB temperature fluctuations, is more challenging. Here we study the technique for…
