Implications of the Cosmic Background Imager Polarization Data

We present new measurements of the power spectra of the E-mode of CMB polarization, the temperature T, the cross-correlation of E and T, and upper limits on the B-mode from 2.5 years of dedicated Cosmic Background Imager (CBI) observations. Both raw maps and optimal signal images in the uv-plane and the sky plane show strong detections of the E-mode (11.7σ for the EE power spectrum overall) and no detection of the B-mode. The power spectra are used to constrain parameters of the flat tilted adiabatic ΛCDMmodels: those determined from EE and TE bandpowers agree with those from TT, a powerful consistency check. There is little tolerance for shifting polarization peaks from the TTforecast locations, as measured by the angular sound crossing scale θ = 100/ls = 1.03± 0.02 from EE and TE cf. 1.044± 0.005 with the TT data included. The scope for extra out-of-phase peaks from subdominant isocurvature modes is also Canadian Institute for Theoretical Astrophysics, University of Toronto, ON M5S 3H8, Canada Departamento de Ingenieŕıa Eléctrica, Universidad de Concepción, Concepción, Chile Departamento de Astronomı́a, Universidad de Chile, Santiago, Chile Department of Physics, Imperial College, London, UK Owens Valley Radio Observatory, California Institute of Technology, Pasadena, CA Astrophysics, Oxford University, Keble Road, Oxford OX1 3RH, UK National Radio Astronomy Observatory, Green Bank, WV 24944 National Radio Astronomy Observatory, Socorro, NM 87801 Kavli Institute for Cosmological Physics, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903