Gas Perturbations in the Cool Cores of Galaxy Clusters: Effective Equation of State, Velocity Power Spectra, and Turbulent Heating

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F18%3A00103888" target="_blank" >RIV/00216224:14310/18:00103888 - isvavai.cz</a>

Result on the web

<a href="https://iopscience.iop.org/article/10.3847/1538-4357/aadae3" target="_blank" >https://iopscience.iop.org/article/10.3847/1538-4357/aadae3</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/aadae3" target="_blank" >10.3847/1538-4357/aadae3</a>

Result language

angličtina

Original language name

Gas Perturbations in the Cool Cores of Galaxy Clusters: Effective Equation of State, Velocity Power Spectra, and Turbulent Heating

Original language description

We present the statistical analysis of X-ray surface brightness and gas density fluctuations in the cool cores of 10 nearby, X-ray-bright galaxy clusters that have deep Chandra observations and show observational indications of radio-mechanical active galactic nucleus (AGN) feedback. Within the central parts of the cool cores, the total variance of fluctuations is dominated by isobaric and/or isothermal fluctuations on spatial scales similar to 10-60 kpc, which are likely associated with slow gas motions and bubbles of relativistic plasma. Adiabatic fluctuations, associated with weak shocks and/or sonic turbulence, constitute less than 10% of the total variance in all clusters. The typical amplitude of density fluctuations is small, similar to 10% or less on scales of similar to 10-15 kpc. The observed subdominant contribution of adiabatic fluctuations and the small amplitude of density fluctuations support a model of gentle AGN feedback. The measured one-component velocities of gas motions are typically below 100-150 km s(-1) on scales &lt;50 kpc and can be up to similar to 300 km s(-1) on similar to 100 kpc scales. The nonthermal energy is &lt;12% of the thermal energy. Regardless of the source that drives these motions, the dissipation of the energy in such motions provides heat that is sufficient to balance radiative cooling on average, albeit with significant uncertainties. The results presented here support previous conclusions based on the analysis of the Virgo and Perseus Clusters and agree with the Hitomi measurements. With next-generation observatories like Athena and Lynx, these techniques will be yet more powerful.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

—

Volume of the periodical

865

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

15

Pages from-to

53-67

UT code for WoS article

000445277100006

EID of the result in the Scopus database

2-s2.0-85053934766