1210.7231 (K. T. Story et al.)

A Measurement of the Cosmic Microwave Background Damping Tail from the 2500-square-degree SPT-SZ survey    [PDF]

K. T. Story, C. L. Reichardt, Z. Hou, R. Keisler, K. A. Aird, B. A. Benson, L. E. Bleem, J. E. Carlstrom, C. L. Chang, H-M. Cho, T. M. Crawford, A. T. Crites, T. de Haan, M. A. Dobbs, J. Dudley, B. Follin, E. M. George, N. W. Halverson, G. P. Holder, W. L. Holzapfel, S. Hoover, J. D. Hrubes, M. Joy, L. Knox, A. T. Lee, E. M. Leitch, M. Lueker, D. Luong-Van, J. J. McMahon, J. Mehl, S. S. Meyer, M. Millea, J. J. Mohr, T. E. Montroy, S. Padin, T. Plagge, C. Pryke, J. E. Ruhl, J. T. Sayre, K. K. Schaffer, L. Shaw, E. Shirokoff, H. G. Spieler, Z. Staniszewski, A. A. Stark, A. van Engelen, K. Vanderlinde, J. D. Vieira, R. Williamson, O. Zahn

We present a measurement of the cosmic microwave background (CMB) temperature power spectrum using data from the recently completed South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey. This measurement is made from observations of 2540 deg^2 of sky with arcminute resolution at 150 GHz, and improves upon previous measurements using the SPT by tripling the sky area. We report CMB temperature anisotropy power over the multipole range 650<\ell<3000. We fit the SPT bandpowers, combined with the results from the seven-year Wilkinson Microwave Anisotropy Probe (WMAP7) data release, with a six-parameter LCDM cosmological model and find that the two datasets are consistent and well fit by the model. Adding SPT measurements significantly improves LCDM parameter constraints, and in particular tightens the constraint on the angular sound horizon \theta_s by a factor of 2.7. The impact of gravitational lensing on the CMB power spectrum is detected with 8.1 \sigma, the most significant detection to date. The inferred amplitude of the lensing spectrum is consistent with the LCDM prediction. This sensitivity of the SPT+WMAP7 data to lensing by large-scale structure at low redshifts allows us to constrain the mean curvature of the observable universe with CMB data alone to be \Omega_K=-0.003+0.014-0.018. Using the SPT+WMAP7 data, we measure the spectral index of scalar fluctuations to be ns=0.9623+/-0.0097 in the LCDM model, a 3.9 \sigma preference for a scale-dependent spectrum with ns<1. The SPT measurement of the CMB damping tail helps break the degeneracy that exists between the tensor-to-scalar ratio r and ns in large-scale CMB measurements, leading to an upper limit of r<0.18 (95% C.L.) in the LCDM+r model. Adding low-redshift measurements of the Hubble constant ($H_0$) and the baryon acoustic oscillation (BAO) feature ...[abridged]

View original: http://arxiv.org/abs/1210.7231