Measurements of B-mode polarization of the cosmic microwave background from 500 square degrees of SPTpol data
We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg 2 of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result,...
Published in: | Physical Review D |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Language: | unknown |
Published: |
2022
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Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1647293 https://www.osti.gov/biblio/1647293 https://doi.org/10.1103/physrevd.101.122003 |
Summary: | We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg 2 of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: 52 < ` < 2301. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: 95 GHz x 95 GHz, 95 GHz x 150 GHz, and 150 GHz x 150 GHz. B-mode power is detected at very high significance; we find P(BB < 0) = 5.8 × 10 -71 , corresponding to a 18.1 σ detection of power. With a prior on the galactic dust from Planck, WMAP and BICEP2/Keck observations, the SPTpol B-mode data can be used to set an upper limit on the tensor-to-scalar ratio, r < 0.44 at 95% confidence (the expected 1 σ constraint on r given the measurement uncertainties is 0.22). We find the measured B-mode power is consistent with the Planck best-fit ΛCDM model predictions. Scaling the predicted lensing B-mode power in this model by a factor A lens , the data prefer A lens = 1.17 ± 0.13. These data are currently the most precise measurements of B-mode power at ℓ > 320. |
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