A Measurement of the Cosmic Microwave Background Damping Tail From the 2500-Square-Degree SPT-Sz Survey

Abstract

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 < < 3000. We fit the SPT bandpowers, combined with the 7 yr Wilkinson Microwave Anisotropy Probe (WMAP7) data, with a six-parameter ΛCDM cosmological model and find that the two datasets are consistent and well fit by the model. Adding SPT measurements significantly improves ΛCDM parameter constraints; in particular, the constraint on θ s tightens by a factor of 2.7. The impact of gravitational lensing is detected at 8.1σ , the most significant detection to date. This sensitivity of the SPT+WMAP7 data to lensing by largescale structure at low redshifts allows us to constrain the mean curvature of the observable universe with CMB data alone to be Ω k = −0.003 +0.014 −0.018 . Using the SPT+WMAP7 data, we measure the spectral index of scalar fluctuations to be n s = 0.9623 ± 0.0097 in the ΛCDM model, a 3.9σ preference for a scale-dependent spectrum with n s < 1. The SPT measurement of the CMB damping tail helps break the degeneracy that exists between the tensor-to-scalar ratio r and n s in large-scale CMB measurements, leading to an upper limit of r < 0.18 (95% C.L.) in the ΛCDM+r model. Adding low-redshift measurements of the Hubble constant (H 0 ) and the baryon acoustic oscillation (BAO) feature to the SPT+WMAP7 data leads to further improvements. The combination of SPT+WMAP7+H 0 +BAO constrains n s = 0.9538 ± 0.0081 in the ΛCDM model, a 5.7σ detection of n s < 1, and places an upper limit of r < 0.11 (95% C.L.) in the ΛCDM+r model. These new constraints on n s and r have significant implications for our understanding of inflation, which we discuss in the context of selected single-field inflation models.

Inflation and String Theory

“…Together with the measurements of the CMB damping tail by the Atacama Cosmology Telescope (ACT) [97,98] and the South Pole Telescope (SPT) [99,100] this provides a beautiful picture of the first seven acoustic peaks of the CMB power spectrum. In this section, we summarize how the CMB results have tested the physics of inflation [9,10].…”

“…CMB observations continue to provide important measurements of the primordial fluctuations, especially on small angular scales [97][98][99][100]. A large number of ground-based and balloon-borne experiments are targeting high-precision measurements of CMB polarization.…”

“…The basic dynamics is similar to that of a charged particle in a magnetic field. 100 As a concrete example, let us consider a stack of N D3-branes, with SU (N ) gauge theory on their worldvolume. The Chern-Simons coupling (3.29) includes the term…”

CMB Polarization B-mode Delensing with SPTpol and Herschel

“…The absolute calibration of these maps is obtained by the process described in C15, in which we calculate the crosspower spectrum between the 150 GHz maps used here and the 150 GHz SPT-SZ maps of the same field, which were in turn calibrated by comparing the temperature power spectrum reported in Story et al (2013) to the Planck Collaboration et al (2014a) temperature power spectrum. The calibration uncertainty resulting from this process is 1.3% in temperature for both the 150 and 95 GHz maps and is almost 100% correlated between these frequencies.…”

Joint measurement of lensing–galaxy correlations using SPT and DES SV data

“…The CMB κ maps used in this work were derived from CMB temperature data taken as part of the 2500 square degree South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey (Story et al 2013). Many observations at 150 GHz of the SPT-E region were combined using inverse-variance weighting to generate a 25 • × 25 • CMB temperature map.…”