Sharpening the Precision of the Sunyaev-Zel'dovich Power Spectrum

Abstract

Using both halo model calculations and a large sample of simulated SZ maps, we demonstrate that high-mass clusters add significant non-Gaussian variance to measurements of the SZ power spectrum amplitude. The difficulty in correctly accounting theoretically for the contribution of these objects to the uncertainty in C_l leads to a reduced sensitivity to σ_8. We show that a simple solution is to mask out the brightest clusters in the map before measuring the power spectrum. We demonstrate that fairly conservative masking can reduce the variance and Gaussianize the statistics significantly, thus increasing the sensitivity to cosmological parameters. Choosing which objects to mask is non-trivial; we found that using a fixed sky density produced a well-defined and well-behaved estimate that can easily be applied to real maps. For example, masking the 10 (90) brightest clusters in a 100 deg^2 SZ map will improve the sensitivity to C_l by a factor of two at l = 1000 (2000) and 1.5 at l = 2000 (4000). We show that even in the presence of astrophysical foregrounds (primary CMB and point sources) and instrument noise, one can increase the precision on measurements of σ_8 by masking up to 0.9 clusters/deg^2.

11 pages, 8 figures, submitted to ApJ

References in corpus (14)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• Catalog Extraction in SZ Cluster Surveys: a matched filter approach
• Astrophysical and Cosmological Information from Large-scale sub-mm Surveys of Extragalactic Sources
• Probing the Dark Matter and Gas Fraction in Relaxed Galaxy Groups with X-ray observations from Chandra and XMM
• The History of Cosmological Star Formation: Three Independent Approaches and a Critical Test Using the Extragalactic Background Light
• Probing dark energy with cluster counts and cosmic shear power spectra: including the full covariance
• Scaling relations and mass calibration of the X-ray luminous galaxy clusters at z~0.2: XMM-Newton observations
• The Impact of Halo Properties, Energy Feedback and Projection Effects on the Mass-SZ Flux Relation
• Final Results from the BIMA CMB Anisotropy Survey and Search for Signature of the SZ effect
• Microwave-Sky Simulations and Projections for Galaxy Cluster Detection with the Atacama Cosmology Telescope
• Adiabatic scaling relations of galaxy clusters
• Efficient Power Spectrum Estimation for High Resolution CMB Maps
• The probability distribution function of the SZ power spectrum: an analytical approach

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• Bispectrum of the Sunyaev-Zel'dovich Effect
• Assessing the Importance of Noise from Thermal Sunyaev-Zel{'}dovich Signals for CMB Cluster Surveys and Cluster Cosmology
• Removable Matter-Power-Spectrum Covariance from Bias Fluctuations
• Accurate estimation of angular power spectra for maps with correlated masks
• Constraining cosmology with thermal Sunyaev-Zel'dovich maps: Minkowski functionals, peaks, minima, and moments
• Simulations and Observations of the Microwave Universe