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Register a new userA 2500 square-degree CMB lensing map from combined South Pole Telescope and Planck data
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We present a cosmic microwave background (CMB) lensing map produced from a linear combination of South Pole Telescope (SPT) and emph{Planck} temperature data. The 150 GHz temperature data from the $2500 {rm deg}^{2}$ SPT-SZ survey is combined with the emph{Planck} 143 GHz data in harmonic space, to obtain a temperature map that has a broader $ell$ coverage and less noise than either individual map. Using a quadratic estimator technique on this combined temperature map, we produce a map of the gravitational lensing potential projected along the line of sight. We measure the auto-spectrum of the lensing potential $C_{L}^{phiphi}$, and compare it to the theoretical prediction for a $Lambda$CDM cosmology consistent with the emph{Planck} 2015 data set, finding a best-fit amplitude of $0.95_{-0.06}^{+0.06}({rm Stat.})! _{-0.01}^{+0.01}({rm Sys.})$. The null hypothesis of no lensing is rejected at a significance of $24,sigma$. One important use of such a lensing potential map is in cross-correlations with other dark matter tracers. We demonstrate this cross-correlation in practice by calculating the cross-spectrum, $C_{L}^{phi G}$, between the SPT+emph{Planck} lensing map and Wide-field Infrared Survey Explorer (emph{WISE}) galaxies. We fit $C_{L}^{phi G}$ to a power law of the form $p_{L}=a(L/L_{0})^{-b}$ with $a=2.15 times 10^{-8}$, $b=1.35$, $L_{0}=490$, and find $eta^{phi G}=0.94^{+0.04}_{-0.04}$, which is marginally lower, but in good agreement with $eta^{phi G}=1.00^{+0.02}_{-0.01}$, the best-fit amplitude for the cross-correlation of emph{Planck}-2015 CMB lensing and emph{WISE} galaxies over $sim67%$ of the sky. The lensing potential map presented here will be used for cross-correlation studies with the Dark Energy Survey (DES), whose footprint nearly completely covers the SPT $2500 {rm deg}^2$ field.
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The South Pole Telescope (SPT) is currently surveying 2500 deg^2 of the southern sky to detect massive galaxy clusters out to the epoch of their formation using the Sunyaev-Zeldovich (SZ) effect. This paper presents a catalog of the 26 most significant SZ cluster detections in the full survey region. The catalog includes 14 clusters which have been previously identified and 12 that are new discoveries. These clusters were identified in fields observed to two differing noise depths: 1500 deg^2 at the final SPT survey depth of 18 uK-arcmin at 150 GHz, and 1000 deg^2 at a depth of 54 uK-arcmin. Clusters were selected on the basis of their SZ signal-to-noise ratio (S/N) in SPT maps, a quantity which has been demonstrated to correlate tightly with cluster mass. The S/N thresholds were chosen to achieve a comparable mass selection across survey fields of both depths. Cluster redshifts were obtained with optical and infrared imaging and spectroscopy from a variety of ground- and space-based facilities. The redshifts range from 0.098 leq z leq 1.132 with a median of z_med = 0.40. The measured SZ S/N and redshifts lead to unbiased mass estimates ranging from 9.8 times 10^14 M_sun/h_70 leq M_200(rho_mean) leq 3.1 times 10^15 M_sun/h_70. Based on the SZ mass estimates, we find that none of the clusters are individually in significant tension with the LambdaCDM cosmological model. We also test for evidence of non-Gaussianity based on the cluster sample and find the data show no preference for non-Gaussian perturbations.
We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the Planck satellite over the patch of sky covered by the SPT-SZ survey. We first visually compare the maps and find that the residuals appear consistent with noise after accounting for differences in angular resolution and filtering. We then calculate (1) the cross-spectrum between two independent halves of SPT data, (2) the cross-spectrum between two independent halves of Planck data, and (3) the cross-spectrum between SPT and Planck data. We find the three cross-spectra are well-fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free calibration parameter---i.e., we find no evidence for systematic errors in either data set. As a by-product, we improve the precision of the SPT calibration by nearly an order of magnitude, from 2.6% to 0.3% in power. Finally, we compare all three cross-spectra to the full-sky Planck power spectrum and find marginal evidence for differences between the power spectra from the SPT-SZ footprint and the full sky. We model these differences as a power law in spherical harmonic multipole number. The best-fit value of this tilt is consistent among the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt is a sample variance fluctuation in the SPT-SZ region relative to the full sky. The consistency of cosmological parameters derived from these datasets is discussed in a companion paper.
We present component-separated maps of the primary cosmic microwave background/kinematic Sunyaev-Zeldovich (SZ) amplitude and the thermal SZ Compton-$y$ parameter, created using data from the South Pole Telescope (SPT) and the Planck satellite. These maps, which cover the $sim$2500 square degrees of the Southern sky imaged by the SPT-SZ survey, represent a significant improvement over previous such products available in this region by virtue of their higher angular resolution (1.25 arcminutes for our highest resolution Compton-$y$ maps) and lower noise at small angular scales. In this work we detail the construction of these maps using linear combination techniques, including our method for limiting the correlation of our lowest-noise Compton-$y$ map products with the cosmic infrared background. We perform a range of validation tests on these data products to test our sky modeling and combination algorithms, and we find good performance in all of these tests. Recognizing the potential utility of these data products for a wide range of astrophysical and cosmological analyses, including studies of the gas properties of galaxies, groups, and clusters, we make these products publicly available at http://pole.uchicago.edu/public/data/sptsz_ymap and on the NASA/LAMBDA website.
We present a measurement of the angular bispectrum of the millimeter-wave sky in observing bands centered at roughly 95, 150, and 220 GHz, on angular scales of $1^prime lesssim theta lesssim 10^prime$ (multipole number $1000 lesssim l lesssim 10000$). At these frequencies and angular scales, the main contributions to the bispectrum are expected to be the thermal Sunyaev-Zeldovich (tSZ) effect and emission from extragalactic sources, predominantly dusty, star-forming galaxies (DSFGs) and active galactic nuclei. We measure the bispectrum in 800 $mathrm{deg}^2$ of three-band South Pole Telescope data, and we use a multi-frequency fitting procedure to separate the bispectrum of the tSZ effect from the extragalactic source contribution. We simultaneously detect the bispectrum of the tSZ effect at $>$10$sigma$, the unclustered component of the extragalactic source bispectrum at $>$5$sigma$ in each frequency band, and the bispectrum due to the clustering of DSFGs---i.e., the clustered cosmic infrared background (CIB) bispectrum---at $>$5$sigma$. This is the first reported detection of the clustered CIB bispectrum. We use the measured tSZ bispectrum amplitude, compared to model predictions, to constrain the normalization of the matter power spectrum to be $sigma_8 = 0.787 pm 0.031$ and to predict the amplitude of the tSZ power spectrum at $l = 3000$. This prediction improves our ability to separate the thermal and kinematic contributions to the total SZ power spectrum. The addition of bispectrum data improves our constraint on the tSZ power spectrum amplitude by a factor of two compared to power spectrum measurements alone and demonstrates a preference for a nonzero kinematic SZ (kSZ) power spectrum, with a derived constraint on the kSZ amplitude at $l=3000$ of A_kSZ $ = 2.9 pm 1.6 mu$K$^2$, or A_kSZ $ = 2.6 pm 1.8 mu$K$^2$ if the default A_kSZ > 0 prior is removed.
We report constraints on cosmological parameters from the angular power spectrum of a cosmic microwave background (CMB) gravitational lensing potential map created using temperature data from 2500 deg$^2$ of South Pole Telescope (SPT) data supplemented with data from Planck in the same sky region, with the statistical power in the combined map primarily from the SPT data. We fit the corresponding lensing angular power spectrum to a model including cold dark matter and a cosmological constant ($Lambda$CDM), and to models with single-parameter extensions to $Lambda$CDM. We find constraints that are comparable to and consistent with constraints found using the full-sky Planck CMB lensing data. Specifically, we find $sigma_8 Omega_{rm m}^{0.25}=0.598 pm 0.024$ from the lensing data alone with relatively weak priors placed on the other $Lambda$CDM parameters. In combination with primary CMB data from Planck, we explore single-parameter extensions to the $Lambda$CDM model. We find $Omega_k = -0.012^{+0.021}_{-0.023}$ or $M_{ u}< 0.70$eV both at 95% confidence, all in good agreement with results that include the lensing potential as measured by Planck over the full sky. We include two independent free parameters that scale the effect of lensing on the CMB: $A_{L}$, which scales the lensing power spectrum in both the lens reconstruction power and in the smearing of the acoustic peaks, and $A^{phi phi}$, which scales only the amplitude of the CMB lensing reconstruction power spectrum. We find $A^{phi phi} times A_{L} =1.01 pm 0.08$ for the lensing map made from combined SPT and Planck temperature data, indicating that the amount of lensing is in excellent agreement with what is expected from the observed CMB angular power spectrum when not including the information from smearing of the acoustic peaks.
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