Measurements of B-mode polarization of the cosmic microwave background from 500 square degrees of SPTpol data

• Published in: Physical Review D
• Main Authors: Sayre, J. T., Reichardt, C. L., Henning, J. W., Ade, P. A. R., Anderson, A. J., Austermann, J. E., Avva, J. S., Beall, J. A., Bender, A. N., Benson, B. A., Bianchini, F., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Chaubal, P., Chiang, H. C., Citron, R., Moran, C. Corbett, Crawford, T. M., Crites, A. T., de Haan, T., Dobbs, M. A., Everett, W., Gallicchio, J., George, E. M., Gilbert, A., Gupta, N., Halverson, N. W., Harrington, N., Hilton, G. C., Holder, G. P., Holzapfel, W. L., Hrubes, J. D., Huang, N., Hubmayr, J., Irwin, K. D., Knox, L., Lee, A. T., Li, D., Lowitz, A., McMahon, J. J., Meyer, S. S., Mocanu, L. M., Montgomery, J., Nadolski, A., Natoli, T., Nibarger, J. P., Noble, G., Novosad, V., Padin, S., Patil, S., Pryke, C., Ruhl, J. E., Saliwanchik, B. R., Schaffer, K. K., Sievers, C., Smecher, G., Stark, A. A., Tucker, C., Vanderlinde, K., Veach, T., Vieira, J. D., Wang, G., Whitehorn, N., Wu, W. L. K., Yefremenko, V., SPTpol Collaboration
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Physical Society 2020
• Subjects: Kavli; South Pole; South pole
• Online Access: https://doi.org/10.1103/physrevd.101.122003

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 deg² 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 < â„“ < 2301. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: 95 GHz × 95 GHz, 95 GHz × 150 GHz, and 150 GHz × 150 GHz. B-mode power is detected at very high significance; we find P(BB < 0) = 5.8 × 10â»â·Â¹, corresponding to a 18.1σ 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 1σ constraint on r given the measurement uncertainties is 0.22). We find the measured B-mode power is consistent with the Planck best-fit Λ CDM 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 â„“ > 320. © 2020 American Physical Society. (Received 23 April 2020; accepted 3 June 2020; published 22 June 2020) The South Pole Telescope program is supported by the National Science Foundation through Grant No. PLR-1248097. Partial support is also provided by the NSF Physics Frontier Center Grant No. PHY-0114422 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation, and the Gordon and Betty Moore Foundation through Grant No. GBMF#947 to the University of Chicago. This work is also supported by the U.S. Department of Energy. The Melbourne authors acknowledge support from an Australian Research Council Future Fellowship (No. FT150100074). J. W. H. is supported by the National Science ...