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@article{1586740,
author = {Zhuravleva, I. and Churazov, E. and Schekochihin, A.A. and Allen, S.W. and Vikhlinin, A. and Werner, Norbert},
article_location = {LONDON},
article_number = {9},
doi = {http://dx.doi.org/10.1038/s41550-019-0794-z},
keywords = {intra-cluster medium},
language = {eng},
issn = {2397-3366},
journal = {NATURE ASTRONOMY},
title = {Suppressed effective viscosity in the bulk intergalactic plasma},
url = {https://arxiv.org/ftp/arxiv/papers/1906/1906.06346.pdf},
volume = {3},
year = {2019}
}
TY - JOUR
ID - 1586740
AU - Zhuravleva, I. - Churazov, E. - Schekochihin, A.A. - Allen, S.W. - Vikhlinin, A. - Werner, Norbert
PY - 2019
TI - Suppressed effective viscosity in the bulk intergalactic plasma
JF - NATURE ASTRONOMY
VL - 3
IS - 9
SP - 832-837
EP - 832-837
PB - NATURE PUBLISHING GROUP
SN - 23973366
KW - intra-cluster medium
UR - https://arxiv.org/ftp/arxiv/papers/1906/1906.06346.pdf
N2 - Transport properties, such as viscosity and thermal conduction, of the hot intergalactic plasma in clusters of galaxies are largely unknown. Whereas for laboratory plasmas these characteristics are derived from the gas density and temperature(1), such recipes can be fundamentally different for the intergalactic plasma(2) owing to a low rate of particle collisions and a weak magnetic field(3). In numerical simulations, these unknowns can often be avoided by modelling these plasmas as hydrodynamic fluids(4-6), even though local, non-hydrodynamic features observed in clusters contradict this assumptions(7-)(9). Using deep Chandra observations of the Coma Cluster(10,11), we probe gas fluctuations in intergalactic medium down to spatial scales where the transport processes should prominently manifest themselves-provided that hydrodynamic models(12) with pure Coulomb collision rates are indeed adequate. We do not find evidence of such transport processes, implying that the effective isotropic viscosity is orders of magnitude smaller than naively expected. This indicates either an enhanced collision rate in the plasma due to particle scattering off microfluctuations caused by plasma instabilities(2,13,24) or that the transport processes are anisotropic with respect to the local magnetic field(15). This also means that numerical models with high Reynolds number appear more consistent with observations. Our results demonstrate that observations of turbulence in clusters(16,17) are giving rise to a branch of astrophysics that can sharpen theoretical views on galactic plasmas.
ER -
ZHURAVLEVA, I., E. CHURAZOV, A.A. SCHEKOCHIHIN, S.W. ALLEN, A. VIKHLININ a Norbert WERNER. Suppressed effective viscosity in the bulk intergalactic plasma. \textit{NATURE ASTRONOMY}. LONDON: NATURE PUBLISHING GROUP, 2019, roč.~3, č.~9, s.~832-837. ISSN~2397-3366. Dostupné z: https://dx.doi.org/10.1038/s41550-019-0794-z.
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