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Title: Gas density fluctuations in the Perseus Cluster: clumping factor and velocity power spectrum

Abstract

X-ray surface brightness fluctuations in the core of the Perseus Cluster are analysed, using deep observations with the Chandra observatory. The amplitude of gas density fluctuations on different scales is measured in a set of radial annuli. It varies from 7 to 12 per cent on scales of ~10–30 kpc within radii of 30–220 kpc from the cluster centre. Using a statistical linear relation between the observed amplitude of density fluctuations and predicted velocity, the characteristic velocity of gas motions on each scale is calculated. The typical amplitudes of the velocity outside the central 30 kpc region are 90–140 km s -1 on ~20–30 kpc scales and 70–100 km s -1 on smaller scales ~7–10 kpc. The velocity power spectrum (PS) is consistent with cascade of turbulence and its slope is in a broad agreement with the slope for canonical Kolmogorov turbulence. The gas clumping factor estimated from the PS of the density fluctuations is lower than 7–8 per cent for radii ~30–220 kpc from the centre, leading to a density bias of less than 3–4 per cent in the cluster core. Uncertainties of the analysis are examined and discussed. Future measurements of the gas velocities with the Astro-H, Athenamore » and Smart-X observatories will directly measure the gas density–velocity perturbation relation and further reduce systematic uncertainties in this analysis.« less

Authors:
; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1335095
Report Number(s):
SLAC-PUB-16739
Journal ID: ISSN 0035-8711; arXiv:1501.07271
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 450; Journal Issue: 4; Journal ID: ISSN 0035-8711
Publisher:
Royal Astronomical Society
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; Astrophysics; ASTRO

Citation Formats

Zhuravleva, I., Churazov, E., Arevalo, P., Schekochihin, A. A., Allen, S. W., Fabian, A. C., Forman, W. R., Sanders, J. S., Simionescu, A., Sunyaev, R., Vikhlinin, A., and Werner, N. Gas density fluctuations in the Perseus Cluster: clumping factor and velocity power spectrum. United States: N. p., 2015. Web. doi:10.1093/mnras/stv900.
Zhuravleva, I., Churazov, E., Arevalo, P., Schekochihin, A. A., Allen, S. W., Fabian, A. C., Forman, W. R., Sanders, J. S., Simionescu, A., Sunyaev, R., Vikhlinin, A., & Werner, N. Gas density fluctuations in the Perseus Cluster: clumping factor and velocity power spectrum. United States. doi:10.1093/mnras/stv900.
Zhuravleva, I., Churazov, E., Arevalo, P., Schekochihin, A. A., Allen, S. W., Fabian, A. C., Forman, W. R., Sanders, J. S., Simionescu, A., Sunyaev, R., Vikhlinin, A., and Werner, N. Wed . "Gas density fluctuations in the Perseus Cluster: clumping factor and velocity power spectrum". United States. doi:10.1093/mnras/stv900. https://www.osti.gov/servlets/purl/1335095.
@article{osti_1335095,
title = {Gas density fluctuations in the Perseus Cluster: clumping factor and velocity power spectrum},
author = {Zhuravleva, I. and Churazov, E. and Arevalo, P. and Schekochihin, A. A. and Allen, S. W. and Fabian, A. C. and Forman, W. R. and Sanders, J. S. and Simionescu, A. and Sunyaev, R. and Vikhlinin, A. and Werner, N.},
abstractNote = {X-ray surface brightness fluctuations in the core of the Perseus Cluster are analysed, using deep observations with the Chandra observatory. The amplitude of gas density fluctuations on different scales is measured in a set of radial annuli. It varies from 7 to 12 per cent on scales of ~10–30 kpc within radii of 30–220 kpc from the cluster centre. Using a statistical linear relation between the observed amplitude of density fluctuations and predicted velocity, the characteristic velocity of gas motions on each scale is calculated. The typical amplitudes of the velocity outside the central 30 kpc region are 90–140 km s-1 on ~20–30 kpc scales and 70–100 km s-1 on smaller scales ~7–10 kpc. The velocity power spectrum (PS) is consistent with cascade of turbulence and its slope is in a broad agreement with the slope for canonical Kolmogorov turbulence. The gas clumping factor estimated from the PS of the density fluctuations is lower than 7–8 per cent for radii ~30–220 kpc from the centre, leading to a density bias of less than 3–4 per cent in the cluster core. Uncertainties of the analysis are examined and discussed. Future measurements of the gas velocities with the Astro-H, Athena and Smart-X observatories will directly measure the gas density–velocity perturbation relation and further reduce systematic uncertainties in this analysis.},
doi = {10.1093/mnras/stv900},
journal = {Monthly Notices of the Royal Astronomical Society},
issn = {0035-8711},
number = 4,
volume = 450,
place = {United States},
year = {2015},
month = {5}
}