Measurement of the electron-pressure profile of galaxy clusters in Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data

Abstract

Using WMAP 3-year data at the locations of close to $\sim 700$ X-ray selected clusters we have detected the amplitude of the thermal Sunyaev-Zeldovich (TSZ) effect at the 15$\sigma$ level, the highest statistical significance reported so far. Owing to the large size of our cluster sample, we are able to detect the corresponding CMB distortions out to large cluster-centric radii. The region over which the TSZ signal is detected is, on average, four times larger in radius than the X-ray emitting region, extending to $\sim 3h_{70}^{-1}$Mpc. We show that an isothermal $\beta$ model does not fit the electron pressure at large radii; instead, the baryon profile is consistent with the Navarro-Frenk-White profile, expected for dark matter in the concordance $\Lambda$CDM model. The X-ray temperature at the virial radius of the clusters falls by a factor $\sim 3-4$ from the central value, depending on the cluster concentration parameter. Our results suggest that cluster dynamics at large radii is dominated by dark matter and is well described by Newtonian gravity.

ApJ Lett, to be published on March 10th, 2008

References in corpus (5)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Temperature profiles of a representative sample of nearby X-ray galaxy clusters
• X-ray and Sunyaev-Zel'dovich Effect Measurements of the Gas Mass Fraction in Galaxy Clusters
• Missing Thermal Energy of the Intracluster Medium
• The Beta-Model Problem: The Incompatibility of X-ray and Sunyaev-Zeldovich Effect Model Fitting for Galaxy Clusters

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• Reconstructing mass profiles of simulated galaxy clusters by combining Sunyaev-Zeldovich and X-ray images
• Cosmological constraints from the observed angular cross-power spectrum between Sunyaev-Zel'dovich and X-ray surveys
• Teaching neural networks to generate Fast Sunyaev Zel'dovich Maps
• Constraints on precipitation-limited hot halos from massive galaxies to galaxy clusters
• The contribution of the kinematic Sunyaev-Zel'dovich Effect from the Warm Hot Intergalactic Medium to the Five-Year WMAP Data
• Probing $f(R)$ gravity with PLANCK data on cluster pressure profiles
• The ${\mathrm{Y}}_{\mathrm{SZ},\mathrm{Planck}}-{\mathrm{Y}}_{\mathrm{SZ},\mathrm{XMM}}$ scaling relation and its difference between cool-core and non-cool-core clusters