Spatially-resolved gas pressure maps of the Coma galaxy cluster are obtained from a mosaic of XMM-Newton observations in the scale range between a resolution of 20 kpc and an extent of 2.8 Mpc. A Fourier analysis of the data reveals the presence of a scale-invariant pressure fluctuation spectrum in the range between 40 and 90 kpc and is found to be well described by a projected Kolmogorov/Oboukhov-type turbulence spectrum. Deprojection and integration of the spectrum yields the lower limit of ∼10 percent of the total intracluster medium pressure in turbulent form. The results also provide observational constraints on the viscosity of the gas.
@article{arxiv.astro-ph/0404132,
title = {Probing Turbulence in the Coma Galaxy Cluster},
author = {P. Schuecker and A. Finoguenov and F. Miniati and H. Boehringer and U. G. Briel},
journal= {arXiv preprint arXiv:astro-ph/0404132},
year = {2009}
}
Comments
12 pages, 13 figures (low resolution), version accepted by Astron. Astrophys