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Discrepancies in the Sunyaev-Zel'dovich Effect Profiles of Galaxy Clusters: Thermal vs. Non-Thermal Contributions

This study examines the discrepancies between the average observed Sunyaev-Zel'dovich (SZ) Effect profiles of 31 galaxy clusters and predictions based on ROSAT data. It reveals that a substantial fraction of the X-ray flux in these clusters is non-thermal, which contributes to discrepancies like hard and soft excess emissions. The research suggests that the SZ Effect may probe non-thermal processes rather than cosmological parameters and highlights the influence of factors like AGN activity, radio emissions, and cluster turbulence on SZ measurements and thermal medium estimations.

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Discrepancies in the Sunyaev-Zel'dovich Effect Profiles of Galaxy Clusters: Thermal vs. Non-Thermal Contributions

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  1. Discrepancy between average WMAP observed and ROSAT predicted Sunyaev-Zel'dovich Effect profiles of 31 clusters (2006 ApJ, 648, 176)

  2. How much is a cluster's 2-7 keV flux thermal? GAL. ABS. x MEKAL SOFT EXCESS HARD EXCESS? Substantial non-thermal fraction of cluster X-ray flux not only explains soft and hard excess, but is also the reason why such a feeble SZ effect among clusters on the whole GAL. ABS. x (MEKAL+PO) POWER-LAW SAME LUMINOSITY AS THERMAL EMISSION!

  3. Giant radio halo A 2163

  4. Zanni et al, A & A, Vol 429, p399 Density Specific Entropy Entropy / Volume

  5. CONSEQUENCES OF ALFVENIC HEATING MODEL • The S-Z effect may be probe of cluster non-thermal processes, not cosmology. • Contribution of thermal medium to cluster mass overestimated when anomalous SZE. Abundances underestimated. • Anomalous S-Z results could be associated with: • active AGN with cluster scale X-ray jets or radio jets • or radio 'ridges‘ • or radio halos • or recent cluster merger. • Full S-Z effect likely in clusters well fitting a thermal temperature distribution, apart from possible cooling flow. • EUV and Hard excess likely where there is large-scale cluster medium turbulence. • Extended cluster radio emission enhancement of the same model • Active cluster medium is a more important cosmic ray source than in our galaxy.

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