2019
Suppressed effective viscosity in the bulk intergalactic plasma
ZHURAVLEVA, I., E. CHURAZOV, A.A. SCHEKOCHIHIN, S.W. ALLEN, A. VIKHLININ et. al.Základní údaje
Originální název
Suppressed effective viscosity in the bulk intergalactic plasma
Autoři
ZHURAVLEVA, I. (643 Rusko), E. CHURAZOV (643 Rusko), A.A. SCHEKOCHIHIN (643 Rusko), S.W. ALLEN (826 Velká Británie a Severní Irsko), A. VIKHLININ (643 Rusko) a Norbert WERNER (703 Slovensko, garant, domácí)
Vydání
NATURE ASTRONOMY, LONDON, NATURE PUBLISHING GROUP, 2019, 2397-3366
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10308 Astronomy
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 11.518
Kód RIV
RIV/00216224:14310/19:00111553
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000485096800014
Klíčová slova anglicky
intra-cluster medium
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 10. 11. 2022 12:17, Mgr. Marie Šípková, DiS.
Anotace
V originále
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.