Can electron distribution functions be derived through the SunyaevZel'dovich effect?
Abstract
Aims: Measurements of the SunyaevZel'dovich (hereafter SZ) effect distortion of the cosmic microwave background provide methods to derive the gas pressure and temperature of galaxy clusters. Here we study the ability of SZ effect observations to derive the electron distribution function (DF) in massive galaxy clusters.
Methods: Our calculations of the SZ effect include relativistic corrections considered within the framework of the Wright formalism and use a decomposition technique of electron DFs into Fourier series. Using multifrequency measurements of the SZ effect, we find the solution of a linear system of equations that is used to derive the Fourier coefficients; we further analyze different frequency samples to decrease uncertainties in Fourier coefficient estimations.
Results: We propose a method to derive DFs of electrons using SZ multifrequency observations of massive galaxy clusters. We found that the best frequency sample to derive an electron DF includes high frequencies ν = 375, 600, 700, 857 GHz. We show that it is possible to distinguish a Juttner DF from a MaxwellBolzman DF as well as from a Juttner DF with the second electron population by means of SZ observations for the best frequency sample if the precision of SZ intensity measurements is less than 0.1%. We demonstrate by means of 3D hydrodynamic numerical simulations of a hot merging galaxy cluster that the morphologies of SZ intensity maps are different for frequencies ν = 375, 600, 700, 857 GHz. We stress that measurements of SZ intensities at these frequencies are a promising tool for studying electron distribution functions in galaxy clusters.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 May 2011
 DOI:
 10.1051/00046361/201016036
 arXiv:
 arXiv:1105.3517
 Bibcode:
 2011A&A...529A..39P
 Keywords:

 galaxies: clusters: intracluster medium;
 relativistic processes;
 cosmic background radiation;
 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 11 pages, 12 figures, published in Astronomy and Astrophysics