Detection of B-Mode Polarization in the Cosmic Microwave Background with Data from the South Pole Telescope
Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This “B-mode” signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave...
Published in: | Physical Review Letters |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Physical Society
2013
|
Subjects: | |
Online Access: | https://authors.library.caltech.edu/42272/ https://authors.library.caltech.edu/42272/1/PhysRevLett.111.141301.pdf https://authors.library.caltech.edu/42272/7/1307.5830v2.pdf https://resolver.caltech.edu/CaltechAUTHORS:20131106-111142604 |
Summary: | Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This “B-mode” signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable. |
---|