The β‐Model Problem: The Incompatibility of X‐Ray and Sunyaev‐Zeldovich Effect Model Fitting for Galaxy Clusters

Abstract
We have analyzed a large sample of numerically simulated clusters to demonstrate the adverse effects resulting from use of X-ray fitted beta-model parameters with Sunyaev-Zeldovich effect (SZE) data. There is a fundamental incompatibility between model fits to X-ray surface brightness profiles and those done with SZE profiles. Since observational SZE radial profiles are in short supply, the X-ray parameters are often used in SZE analysis. We show that this leads to biased estimates of the integrated Compton y-parameter inside r_{500} calculated from clusters. We suggest a simple correction of the method, using a non-isothermal beta-model modified by a universal temperature profile, which brings these calculated quantities into closer agreement with the true values.Comment: Accepted to The Astrophysical Journal, 10 pages, 9 figures, emulateapj styl
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