Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season

Journal Article · Mon Oct 04 00:00:00 EDT 2021 · Physical Review Letters

DOI:https://doi.org/10.1103/physrevlett.127.151301· OSTI ID:1870843

Ade, P.  A. R. ^[1]; Ahmed, Z.; Amiri, M.; Barkats, D.; Thakur, R. Basu; Bischoff, C.  A.; Beck, D.; Bock, J.  J.; Boenish, H.; Bullock, E.; Buza, V.; Cheshire, J.  R.; Connors, J.; Cornelison, J.; Crumrine, M.; Cukierman, A.; Denison, E.  V.; Dierickx, M.; Duband, L.; Eiben, M. ; Fatigoni, S.; Filippini, J.  P.; Fliescher, S.; Goeckner-Wald, N.; Goldfinger, D.  C.; Grayson, J.; Grimes, P.; Hall, G.; Halal, G.; Halpern, M.; Hand, E.; Harrison, S.; Henderson, S.; Hildebrandt, S.  R.; Hilton, G.  C.; Hubmayr, J.; Hui, H.; Irwin, K.  D.; Kang, J.; Karkare, K.  S.; Karpel, E.; Kefeli, S.; Kernasovskiy, S.  A.; Kovac, J.  M.; Kuo, C.  L.; Lau, K.; Leitch, E.  M.; Lennox, A.; Megerian, K.  G.; Minutolo, L.; Moncelsi, L.; Nakato, Y.; Namikawa, T.; Nguyen, H.  T.; O’Brient, R.; Ogburn, R.  W.; Palladino, S.; Prouve, T.; Pryke, C.; Racine, B.; Reintsema, C.  D.; Richter, S.; Schillaci, A.; Schwarz, R.; Schmitt, B.  L.; Sheehy, C.  D.; Soliman, A.; Germaine, T.  St.; Steinbach, B.; Sudiwala, R.  V.; Teply, G.  P.; Thompson, K.  L.; Tolan, J.  E.; Tucker, C.; Turner, A.  D.; Umiltà, C.; Vergès, C.; Vieregg, A.  G.; Wandui, A.; Weber, A.  C.; Wiebe, D.  V.; Willmert, J.; Wong, C.  L.; Wu, W.  L. K.; Yang, H.; Yoon, K.  W.; Young, E.; Yu, C.; Zeng, L.; Zhang, C.; Zhang, S.

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1. Cardiff Univ., Wales (United Kingdom); BICEP/Keck Collaboration. et al.

Here, we present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to and including the 2018 observing season. We add additional Keck Array observations at 220 GHz and BICEP3 observations at 95 GHz to the previous 95/150/220 GHz dataset. The Q/U maps now reach depths of 2.8, 2.8, and 8.8 μK_CMB arcmin at 95,150, and 220 GHz, respectively, over an effective area of ≈ 600 square degrees at 95 GHz and ≈ 400 square degrees at 150 and 220 GHz. The 220 GHz maps now achieve a signal-to-noise ratio on polarized dust emission exceeding that of Planck at 353 GHz. We take auto- and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz and evaluate the joint likelihood of the spectra versus a multicomponent model of lensed ΛCDM + r + dust + synchrotron + noise . The foreground model has seven parameters, and no longer requires a prior on the frequency spectral index of the dust emission taken from measurements on other regions of the sky. This model is an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r _0.05 < 0.036 at 95% confidence. Running maximum likelihood search on simulations we obtain unbiased results and find that σ(r) = 0.009 . These are the strongest constraints to date on primordial gravitational waves.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF); National Aeronautical and Space Administration (NASA)
• Contributing Organization: BICEP/Keck Collaboration
• Grant/Contract Number: AC02-76SF00515; 0742818; 0742592; 1044978; 1110087; 1145172; 1145143; 1145248; 1639040; 1638957; 1638978; 1638970; 06-ARPA206-0040; 10-SAT10-0017; 12- SAT12-0031; 14-SAT14-0009; 16-SAT-16- 0002
• OSTI ID: 1870843
• Journal Information: Physical Review Letters, Vol. 127, Issue 15; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

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