A MEASUREMENT OF GRAVITATIONAL LENSING OF THE MICROWAVE BACKGROUND USING SOUTH POLE TELESCOPE DATA

By A. V. Engelen, R. Keisler, Oliver Zahn, K. Aird, B. Benson, L. Bleem, J. Carlstrom, C. Chang, Hsiao-mei Cho, T. Crawford and 40 more. 2012

210 citations recorded by the source corpus.

We use South Pole Telescope data from 2008 and 2009 to detect the non-Gaussian signature in the cosmic microwave background (CMB) produced by gravitational lensing and to measure the power spectrum of the projected gravitational potential. We constrain the ratio of the measured amplitude of the lensing signal to that expected in a fiducial ΛCDM cosmological model to be 0.86 ± 0.16, with no lensing disfavored at 6.3σ. Marginalizing over ΛCDM cosmological models allowed by the Wilkinson Microwave Anisotropy Probe (WMAP7) results in a measurement of Alens = 0.90 ± 0.19, indicating that the amplitude of matter fluctuations over the redshift range 0.5 ≲ z ≲ 5 probed by CMB lensing is in good agreement with predictions. We present the results of several consistency checks. These include a clear detection of the lensing signature in CMB maps filtered to have no overlap in Fourier space, as well as a “curl” diagnostic that is consistent with the signal expected for ΛCDM. We perform a detailed study of bias in the measurement due to noise, foregrounds, and other effects and determine that these contributions are relatively small compared to the statistical uncertainty in the measurement. We combine this lensing measurement with results from WMAP7 to improve constraints on cosmological parameters when compared to those from WMAP7 alone: we find a factor of 3.9 improvement in the measurement of the spatial curvature of the universe, Ωk = −0.0014 ± 0.0172; a 10% improvement in the amplitude of matter fluctuations within ΛCDM, σ8 = 0.810 ± 0.026; and a 5% improvement in the dark energy equation of state, w = −1.04 ± 0.40. When compared with the measurement of w provided by the combination of WMAP7 and external constraints on the Hubble parameter, the addition of the lensing data improves the measurement of w by 15% to give w = −1.087 ± 0.096.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/1b4be3bb2eb267f910b22c28d31decd8ed4dd821

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Citations in the corpus

The Atacama Cosmology Telescope: temperature and gravitational lensing power spectrum measurements from three seasons of data (2013, background): “The lensing power spectrum measurements presented here and by SPT [47] are the first steps along this new path.”
Detection of B-mode polarization at degree angular scales by BICEP2. (2014, methodology): “For the increased channel count in BICEP2 this is computationally very expensive, so we have switched to an alternate procedure adapted from van Engelen et al. (2012).”
A MEASUREMENT OF THE COSMIC MICROWAVE BACKGROUND DAMPING TAIL FROM THE 2500-SQUARE-DEGREE SPT-SZ SURVEY (2012, methodology): “CMB lensing has also been detected through the CMB temperature four-point function in ACT (Das et al. 2011b) and SPT (van Engelen et al. 2012) data.”
Elucidating ΛCDM: Impact of Baryon Acoustic Oscillation Measurements on the Hubble Constant Discrepancy (2017, methodology): “…Telescope polarization-sensitive receiver (ACTPol; Thornton et al. 2016; Louis et al. 2017; Sherwin et al. 2016) two-season survey, covering 548 deg2, and the 2500 deg2 South Pole Telescope Sunyaev-Zel’dovich survey (SPT-SZ; Carlstrom et al. 2011; Story et al. 2013; van Engelen et al. 2012).”
Dusty Star Forming Galaxies at High Redshift (2014, methodology): “…background (CMB) by large-scale structure dark matter distribution has now been detected with arcminute-scale CMB experiments, such as the South Pole Telescope (van Engelen et al., 2012) and the Atacama Cosmology Telescope (Das et al., 2013) and with Planck (Planck Collaborationet al., 2013c).”
THE COYOTE UNIVERSE EXTENDED: PRECISION EMULATION OF THE MATTER POWER SPECTRUM (2013, methodology): “In the CMB, high-resolution measurements by the Atacama Cosmology telescope (ACT; Das et al. 2011) and the South Pole Telescope (SPT; van Engelen et al. 2012) have confirmed the sensitivity of the CMB to the large scale distribution of matter (CMB lensing).”
The Quest for B Modes from Inflationary Gravitational Waves (2015, methodology): “…of lensing of the WMAP temperature map were discovered through cross-correlation with the NVSS radio survey (Smith, Zahn & Dore 2007) and several other tracers of the mass distribution (Hirata et al. 2008) and then through autocorrelation in ACT (Das et al. 2011) and SPT (van Engelen et al. 2012).”
NINE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: COSMOLOGICAL PARAMETER RESULTS (2012, methodology): “In addition to the temperature spectra, both ACT and SPT have estimated the deflection spectra due to gravitational lensing (Das et al. 2011a; van Engelen et al. 2012).”
SPTpol: an instrument for CMB polarization measurements with the South Pole Telescope (2012, background): “Comparing the gravitational lensing of the CMB to galaxy surveys or other external mass tracers provides another source of constraint on dark energy and structure formation.(10,26) Fine scale anisotropies are also sensitive to the expansion rate during recombination and thus to the number of relativ”
Observational probes of cosmic acceleration (2012, methodology): “The advent of the arcminute-scale CMB experiments ACT and SPT (primarily motivated by cluster cosmology using the SZ effect) has enabled robust detections of the power spectrum of the CMB lensing field (Das et al., 2011; van Engelen et al., 2012).”
GALAXY CLUSTERS DISCOVERED VIA THE SUNYAEV–ZEL’DOVICH EFFECT IN THE FIRST 720 SQUARE DEGREES OF THE SOUTH POLE TELESCOPE SURVEY (2012, background): “…and secondary CMB anisotropy (Keisler et al. 2011; Lueker et al. 2010; Shirokoff et al. 2011; Reichardt et al. 2011), a measurement of gravitational lensing of the CMB (van Engelen et al. 2012), and the discovery of a new population of extremely bright submillimeter galaxies (Vieira et al. 2010).”
A MEASUREMENT OF THE COSMIC MICROWAVE BACKGROUND B-MODE POLARIZATION POWER SPECTRUM AT SUB-DEGREE SCALES WITH POLARBEAR (2014, methodology): “…CMB by LSS was first observed in temperature measurements, through the LSS-induced nonGaussianities (Smith et al. 2007; Das et al. 2011, 2013; van Engelen et al. 2012; Planck Collaboration 2013c), and modification of the power spectrum CTT` (Calabrese et al. 2008; Reichardt et al. 2009; Das et…”
PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper (2013, methodology): “B anisotropies via subtle distortions imprinted on the statistics of the CMB by the lenses [102,220]. This approach has been demonstrated recently for the temperature anisotropies by ACT [58,59], SPT [214] andPlanck [163], with the latter detecting the lensing power spectrum at the 25˙level. Lensing”