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Register a new userCluster Cosmology Constraints from the 2500 deg$^2$ SPT-SZ Survey: Inclusion of Weak Gravitational Lensing Data from Magellan and the Hubble Space Telescope
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We derive cosmological constraints using a galaxy cluster sample selected from the 2500~deg$^2$ SPT-SZ survey. The sample spans the redshift range $0.25< z<1.75$ and contains 343 clusters with SZ detection significance $xi>5$. The sample is supplemented with optical weak gravitational lensing measurements of 32 clusters with $0.29<z<1.13$ (from Magellan and HST) and X-ray measurements of 89 clusters with $0.25<z<1.75$ (from Chandra). We rely on minimal modeling assumptions: i) weak lensing provides an accurate means of measuring halo masses, ii) the mean SZ and X-ray observables are related to the true halo mass through power-law relations in mass and dimensionless Hubble parameter $E(z)$ with a-priori unknown parameters, iii) there is (correlated, lognormal) intrinsic scatter and measurement noise relating these observables to their mean relations. We simultaneously fit for these astrophysical modeling parameters and for cosmology. Assuming a flat $ uLambda$CDM model, in which the sum of neutrino masses is a free parameter, we measure $Omega_mathrm{m}=0.276pm0.047$, $sigma_8=0.781pm0.037$, and $sigma_8(Omega_mathrm{m}/0.3)^{0.2}=0.766pm0.025$. The redshift evolution of the X-ray $Y_mathrm{X}$-mass and $M_mathrm{gas}$-mass relations are both consistent with self-similar evolution to within $1sigma$. The mass-slope of the $Y_mathrm{X}$-mass relation shows a $2.3sigma$ deviation from self-similarity. Similarly, the mass-slope of the $M_mathrm{gas}$-mass relation is steeper than self-similarity at the $2.5sigma$ level. In a $ u w$CDM cosmology, we measure the dark energy equation of state parameter $w=-1.55pm0.41$ from the cluster data. We perform a measurement of the growth of structure since redshift $zsim1.7$ and find no evidence for tension with the prediction from General Relativity. We provide updated redshift and mass estimates for the SPT sample. (abridged)
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We explore extensions to the $Lambda$CDM cosmology using measurements of the cosmic microwave background (CMB) from the recent SPT-SZ survey, along with data from WMAP7 and measurements of $H_0$ and BAO. We check for consistency within $Lambda$CDM between these datasets, and find some tension. The CMB alone gives weak support to physics beyond $Lambda$CDM, due to a slight trend relative to $Lambda$CDM of decreasing power towards smaller angular scales. While it may be due to statistical fluctuation, this trend could also be explained by several extensions. We consider running index (nrun), as well as two extensions that modify the damping tail power (the primordial helium abundance $Y_p$ and the effective number of neutrino species $N_{rm eff}$) and one that modifies the large-scale power due to the ISW effect (the sum of neutrino masses $sum m_ u$). These extensions have similar observational consequences and are partially degenerate when considered simultaneously. Of the 6 one-parameter extensions considered, we find CMB to have the largest preference for nrun with -0.046<nrun<-0.003 at 95% confidence, which strengthens to a 2.7$sigma$ indication of nrun<0 from CMB+BAO+$H_0$. Detectable non-zero nrun is difficult to explain in the context of single-field, slow-roll inflation models. We find $N_{rm eff}=3.62pm0.48$ for the CMB, which tightens to $N_{rm eff}=3.71pm0.35$ from CMB+BAO+$H_0$. Larger values of $N_{rm eff}$ relieve the mild tension between CMB, BAO and $H_0$. When the SZ selected galaxy cluster abundances ($rm{SPT_{CL}}$) data are also included, we obtain $N_{rm eff}=3.29pm0.31$. Allowing for $sum m_ u$ gives a 3$sigma$ detection of $sum m_ u$>0 from CMB+BAO+$H_0$+$rm{SPT_{CL}}$. The median value is $(0.32pm0.11)$ eV, a factor of six above the lower bound set by neutrino oscillation observations. ... [abridged]
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.
We present three maps of the millimeter-wave sky created by combining data from the South Pole Telescope (SPT) and the Planck satellite. We use data from the SPT-SZ survey, a survey of 2540 deg$^2$ of the the sky with arcminute resolution in three bands centered at 95, 150, and 220 GHz, and the full-mission Planck temperature data in the 100, 143, and 217 GHz bands. A linear combination of the SPT-SZ and Planck data is computed in spherical harmonic space, with weights derived from the noise of both instruments. This weighting scheme results in Planck data providing most of the large-angular-scale information in the combined maps, with the smaller-scale information coming from SPT-SZ data. A number of tests have been done on the maps. We find their angular power spectra to agree very well with theoretically predicted spectra and previously published results.
(abridged) We present cosmological constraints obtained from galaxy clusters identified by their Sunyaev-Zeldovich effect signature in the 2500 square degree South Pole Telescope Sunyaev Zeldovich survey. We consider the 377 cluster candidates identified at z>0.25 with a detection significance greater than five, corresponding to the 95% purity threshold for the survey. We compute constraints on cosmological models using the measured cluster abundance as a function of mass and redshift. We include additional constraints from multi-wavelength observations, including Chandra X-ray data for 82 clusters and a weak lensing-based prior on the normalization of the mass-observable scaling relations. Assuming a LCDM cosmology, where the species-summed neutrino mass has the minimum allowed value (mnu = 0.06 eV) from neutrino oscillation experiments, we combine the cluster data with a prior on H0 and find sigma_8 = 0.797+-0.031 and Omega_m = 0.289+-0.042, with the parameter combination sigma_8(Omega_m/0.27)^0.3 = 0.784+-0.039. These results are in good agreement with constraints from the CMB from SPT, WMAP, and Planck, as well as with constraints from other cluster datasets. Adding mnu as a free parameter, we find mnu = 0.14+-0.08 eV when combining the SPT cluster data with Planck CMB data and BAO data, consistent with the minimum allowed value. Finally, we consider a cosmology where mnu and N_eff are fixed to the LCDM values, but the dark energy equation of state parameter w is free. Using the SPT cluster data in combination with an H0 prior, we measure w = -1.28+-0.31, a constraint consistent with the LCDM cosmological model and derived from the combination of growth of structure and geometry. When combined with primarily geometrical constraints from Planck CMB, H0, BAO and SNe, adding the SPT cluster data improves the w constraint from the geometrical data alone by 14%, to w = -1.023+-0.042.
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.
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