Abstract
We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol survey at the locations of roughly 18 000 clusters with richness from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at . The mean stacked mass of the selected sample is found to be which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.
- Received 30 July 2019
DOI:https://doi.org/10.1103/PhysRevLett.123.181301
© 2019 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Polarization of Cosmic Microwave Background Reveals Mass of Galaxy Clusters
Published 31 October 2019
The first detection of gravitational lensing in the polarization pattern of the cosmic microwave background offers a more precise way to measure the mass of galaxy clusters.
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