The Gravitational Lensing Imprints of DES Y3 Superstructures on the CMB: A Matched Filtering Approach
arxiv(2024)
摘要
Low density cosmic voids gravitationally lens the cosmic microwave
background (CMB), leaving a negative imprint on the CMB convergence κ.
This effect provides insight into the distribution of matter within voids, and
can also be used to study the growth of structure. We measure this lensing
imprint by cross-correlating the Planck CMB lensing convergence map with voids
identified in the Dark Energy Survey Year 3 data set, covering approximately
4,200 deg^2 of the sky. We use two distinct void-finding algorithms: a 2D
void-finder which operates on the projected galaxy density field in thin
redshift shells, and a new code, Voxel, which operates on the full 3D map of
galaxy positions. We employ an optimal matched filtering method for
cross-correlation, using the MICE N-body simulation both to establish the
template for the matched filter and to calibrate detection significances. Using
the DES Y3 photometric luminous red galaxy sample, we measure A_κ, the
amplitude of the observed lensing signal relative to the simulation template,
obtaining A_κ = 1.03 ± 0.22 (4.6σ significance) for Voxel and
A_κ = 1.02 ± 0.17 (5.9σ significance) for 2D voids, both
consistent with ΛCDM expectations. We additionally invert the 2D
void-finding process to identify superclusters in the projected density field,
for which we measure A_κ = 0.87 ± 0.15 (5.9σ significance). The
leading source of noise in our measurements is Planck noise, implying that
future data from the Atacama Cosmology Telescope (ACT), South Pole Telescope
(SPT) and CMB-S4 will increase sensitivity and allow for more precise
measurements.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要