Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Constraints on primordial gravitational waves using Planck , WMAP, and new BICEP2/ Keck observations through the 2015 season

Ade, P.A.R ORCID:, Ahmed, Z., Aikin, R.W., Alexander, K.D., Barkats, D., Benton, S.J., Bischoff, C.A., Bock, J.J., Bowens-Rubin, R., Brevik, J.A., Buder, I., Bullock, E., Buza, V., Connors, J., Cornelison, J., Crill, B.P., Crumrine, M., Dierickx, M., Duband, L., Dvorkin, C., Filippini, J.P., Fliescher, S., Grayson, J., Hall, G., Halpern, M., Harrison, S., Hildebrandt, S.R., Hilton, G.C., Hui, H., Irwin, K.D., Kang, J., Karkare, K.S., Karpel, E., Kaufman, J.P., Keating, B.G., Kefeli, S., Kernasovskiy, S.A., Kovac, J.M., Kuo, C.L., Larsen, N.A., Lau, K., Leitch, E.M., Lueker, M., Megerian, K.G., Moncelsi, L., Namikawa, T., Netterfield, C.B., Nguyen, H.T., O'Brient, R., Ogburn, R.W., Palladino, S., Pryke, C., Racine, B., Richter, S., Schillaci, A., Schwarz, R., Sheehy, C.D., Soliman, A., St.Germaine, T., Staniszewski, Z.K., Steinbach, B., Sudiwala, R.V. ORCID:, Teply, G.P., Thompson, K.L., Tolan, J.E., Tucker, C., Turner, A.D., Umiltà, 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. and Zhang, C. 2018. Constraints on primordial gravitational waves using Planck , WMAP, and new BICEP2/ Keck observations through the 2015 season. Physical Review Letters 121 (22) , 221301. 10.1103/PhysRevLett.121.221301

[thumbnail of PhysRevLett.121.221301.pdf]
PDF - Published Version
Download (1MB) | Preview


We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including the 2015 observing season. This includes the first Keck Array observations at 220 GHz and additional observations at 95 and 150 GHz. The Q and U maps reach depths of 5.2, 2.9, and 26  μKCMB arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈400 square degrees. The 220 GHz maps achieve a signal to noise on polarized dust emission approximately equal to 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. We 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 we impose priors on some of these using external information from Planck and WMAP derived from larger regions of sky. The model is shown to be an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r0.05<0.07 at 95% confidence, which tightens to r0.05<0.06 in conjunction with Planck temperature measurements and other data. The lensing signal is detected at 8.8σ significance. Running a maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.020. These are the strongest constraints to date on primordial gravitational waves.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Publisher: American Physical Society
ISSN: 0031-9007
Date of First Compliant Deposit: 20 December 2018
Date of Acceptance: 27 November 2018
Last Modified: 06 May 2023 22:27

Citation Data

Cited 293 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics