2003/02/28 by J. M. Diego, Joseph Silk, J. Silk +2 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #CMB cold spot #Correlation #Cosmic microwave background #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Galaxy #Optics #Physics #ROSAT #Sigma #Spectral density #Statistics #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2003.07150.x
published as Mon.Not.Roy.Astron.Soc. 346 (2003) 940 · This is the accepted version of the paper
arxiv created 2003/09/03 · openalex publication_date 2003/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We cross-correlate WMAP and ROSAT diffuse X-ray background maps and look for common features in both data sets. We use the power spectrum of the product maps and the cross-power spectrum to highlight a possible correlation. The power spectrum of the product maps does not detect any correlation and the cross-power spectrum does not show any significant deviation from 0. We explore different explanations for this lack of correlation. A universe with a low value of Sigma8 could naturally explain the lack of correlation. We also discuss the systematic effects which can affect this result, in particular the subtraction of some cluster signal from the ROSAT diffuse maps which could significantly suppress the correlation signal. These systematic effects reduce considerably the significance of our constraints on the cosmological model. When we include the systematic effects we find a weaker constrain on Sigma8 allowing models with values as large as Sigma8=1 (for Omegam = 0.3) to be consistent with the lack of correlation. To illustrate the capabilities of the method with future high-quality data, we show how from the correlation signal it should be possible to predict the level of contamination of the SZ effect on the power spectrum of the CMB. Within the systematic errors we find evidence that this contribution is negligible for WMAP and is expected to be small in experiments like ACBAR or CBI, but can be important for future high resolution experiments.