Joint measurements of thermal Sunyaev-Zel'dovich and cosmic infrared background cross-correlations with cosmic shear
Abstract
The cross-correlation between weak lensing (WL) and the thermal Sunyaev-Zel'dovich (tSZ) effect probes the connection between the matter distribution and the thermal state of baryons at low redshift (z≲1). A key systematic in such measurements is contamination by extragalactic foregrounds, particularly the cosmic infrared background (CIB). Here we describe the CIB spectral energy distribution (SED) with a small number of physically motivated spectral parameters, calibrated against external measurements of the radiation field intensity in galaxies. Their uncertainty is then propagated into the recovered WL×tSZ signal in component separation at the level of the multi-frequency cross-power spectra rather than the map level. Applying this method to cosmic shear from the Dark Energy Survey and frequency maps from Planck, we show that the resulting measurements of the WL×tSZ power spectrum are insensitive to variations in the effective CIB spectral index, radio source contamination, and the scale and redshift dependence of the SED. The measurements are robust to realistic foreground uncertainties, supporting their use as probes of baryonic feedback and cosmology, and providing a framework for future high-precision surveys. We compare our measurements with the Flamingo suite of hydrodynamical simulations and find that they are compatible with the Flamingo predictions for a low amplitude of matter fluctuations, parametrised by S8, strongly disfavouring the larger S8 preferred by Planck. This result is independent of the impact of baryonic feedback as modelled in Flamingo.
Related
- The impact of feedback and cosmology on Cosmic Infrared Background cross-correlations
- Constraining Effective Viscosity in the Intracluster Medium via the Thermal Sunyaev-Zeldovich Effect -- Predictions from the SLOW Constrained Coma Cluster Simulations
- Joint X-Ray, Kinetic Sunyaev–Zeldovich, and Weak Lensing Measurements: Toward a Consensus Picture of Efficient Gas Expulsion from Groups and Clusters
- Field-level inference under pressure: the information content of the thermal Sunyaev-Zel'dovich field
- Thermal Sunyaev-Zel'dovich Effect in the circumgalactic medium - III: does richness matter?
BibTeX
@misc{wayland2026joint,
title = {{Joint measurements of thermal Sunyaev-Zel'dovich and cosmic infrared background cross-correlations with cosmic shear}},
author = {Amy Wayland and Adrien La Posta and David Alonso and Baptiste Jego and Matthieu Béthermin},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.31774},
eprint = {2609.31774},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05830214v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Joint measurements of thermal Sunyaev-Zel'dovich and cosmic infrared background cross-correlations with cosmic shear
AU - Amy Wayland
AU - Adrien La Posta
AU - David Alonso
AU - Baptiste Jego
AU - Matthieu Béthermin
PY - 2026
DA - 2026/09/24
PB - HAL
DO - 10.48550/arxiv.2609.31774
UR - https://hal.science/hal-05830214v1
AB - The cross-correlation between weak lensing (WL) and the thermal Sunyaev-Zel'dovich (tSZ) effect probes the connection between the matter distribution and the thermal state of baryons at low redshift (z≲1). A key systematic in such measurements is contamination by extragalactic foregrounds, particularly the cosmic infrared background (CIB). Here we describe the CIB spectral energy distribution (SED) with a small number of physically motivated spectral parameters, calibrated against external measurements of the radiation field intensity in galaxies. Their uncertainty is then propagated into the recovered WL×tSZ signal in component separation at the level of the multi-frequency cross-power spectra rather than the map level. Applying this method to cosmic shear from the Dark Energy Survey and frequency maps from Planck, we show that the resulting measurements of the WL×tSZ power spectrum are insensitive to variations in the effective CIB spectral index, radio source contamination, and the scale and redshift dependence of the SED. The measurements are robust to realistic foreground uncertainties, supporting their use as probes of baryonic feedback and cosmology, and providing a framework for future high-precision surveys. We compare our measurements with the Flamingo suite of hydrodynamical simulations and find that they are compatible with the Flamingo predictions for a low amplitude of matter fluctuations, parametrised by S_8, strongly disfavouring the larger S_8 preferred by Planck. This result is independent of the impact of baryonic feedback as modelled in Flamingo.
ER -