English

The Beta-Model Problem: The Incompatibility of X-ray and Sunyaev-Zeldovich Effect Model Fitting for Galaxy Clusters

Astrophysics 2009-06-23 v1

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.

Keywords

Cite

@article{arxiv.0705.0531,
  title  = {The Beta-Model Problem: The Incompatibility of X-ray and Sunyaev-Zeldovich Effect Model Fitting for Galaxy Clusters},
  author = {Eric J. Hallman and Jack O. Burns and Patrick M. Motl and Michael L. Norman},
  journal= {arXiv preprint arXiv:0705.0531},
  year   = {2009}
}

Comments

Accepted to The Astrophysical Journal, 10 pages, 9 figures, emulateapj style