MASS CALIBRATION AND COSMOLOGICAL ANALYSIS OF THE SPT-SZ GALAXY CLUSTER SAMPLE USING VELOCITY DISPERSION σ[subscript v] AND X-RAY Y[subscript X] MEASUREMENTS

We present a velocity-dispersion-based mass calibration of the South Pole Telescope Sunyaev-Zel'dovich effect survey (SPT-SZ) galaxy cluster sample. Using a homogeneously selected sample of 100 cluster candidates from 720 deg[superscript 2] of the survey along with 63 velocity dispersion (σ [su...

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Bibliographic Details
Main Authors: Bautz, Marshall W. (Contributor), McDonald, Michael A. (Contributor)
Other Authors: MIT Kavli Institute for Astrophysics and Space Research (Contributor)
Format: Article
Language:English
Published: IOP Publishing, 2015-04-24T14:51:41Z.
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Online Access:Get fulltext
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100 1 0 |a Bautz, Marshall W.  |e author 
100 1 0 |a MIT Kavli Institute for Astrophysics and Space Research  |e contributor 
100 1 0 |a Bautz, Marshall W.  |e contributor 
100 1 0 |a McDonald, Michael A.  |e contributor 
700 1 0 |a McDonald, Michael A.  |e author 
245 0 0 |a MASS CALIBRATION AND COSMOLOGICAL ANALYSIS OF THE SPT-SZ GALAXY CLUSTER SAMPLE USING VELOCITY DISPERSION σ[subscript v] AND X-RAY Y[subscript X] MEASUREMENTS 
260 |b IOP Publishing,   |c 2015-04-24T14:51:41Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/96785 
520 |a We present a velocity-dispersion-based mass calibration of the South Pole Telescope Sunyaev-Zel'dovich effect survey (SPT-SZ) galaxy cluster sample. Using a homogeneously selected sample of 100 cluster candidates from 720 deg[superscript 2] of the survey along with 63 velocity dispersion (σ [subscript v]) and 16 X-ray Y [subscript X] measurements of sample clusters, we simultaneously calibrate the mass-observable relation and constrain cosmological parameters. Our method accounts for cluster selection, cosmological sensitivity, and uncertainties in the mass calibrators. The calibrations using σ [subscript v] and Y [subscript X] are consistent at the 0.6σ level, with the σ [subscript v] calibration preferring ~16% higher masses. We use the full SPT[subscript CL] data set (SZ clusters+σ [subscript v] +Y [subscript X]) to measure σ[subscript 8](Ω[subscript m]/0.27)[superscript 0.3] = 0.809 ± 0.036 within a flat ΛCDM model. The SPT cluster abundance is lower than preferred by either the WMAP9 or Planck+WMAP9 polarization (WP) data, but assuming that the sum of the neutrino masses is ∑m [subscript ν] = 0.06 eV, we find the data sets to be consistent at the 1.0σ level for WMAP9 and 1.5σ for Planck+WP. Allowing for larger ∑m [subscript ν] further reconciles the results. When we combine the SPT[subscript CL] and Planck+WP data sets with information from baryon acoustic oscillations and Type Ia supernovae, the preferred cluster masses are 1.9σ higher than the Y [subscript X] calibration and 0.8σ higher than the σ [subscript v] calibration. Given the scale of these shifts (~44% and ~23% in mass, respectively), we execute a goodness-of-fit test; it reveals no tension, indicating that the best-fit model provides an adequate description of the data. Using the multi-probe data set, we measure Ω[subscript m] = 0.299 ± 0.009 and σ[subscript 8] = 0.829 ± 0.011. Within a νCDM model we find ∑m [subscript ν] = 0.148 ± 0.081 eV. We present a consistency test of the cosmic growth rate using SPT clusters. Allowing both the growth index γ and the dark energy equation-of-state parameter w to vary, we find γ = 0.73 ± 0.28 and w = -1.007 ± 0.065, demonstrating that the expansion and the growth histories are consistent with a ΛCDM universe (γ = 0.55; w = -1). 
546 |a en_US 
655 7 |a Article 
773 |t The Astrophysical Journal