Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback

Statistical analysis of Faraday rotation measure (RM) maps of the intracluster medium (ICM) of galaxy clusters provides a unique tool to evaluate some spatial features of the magnetic fields there. Its combination with numerical simulations of magnetohydrodynamic (MHD) turbulence allows the diagnosi...

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Autores principales:	Santos-Lima, R., de Gouveia Dal Pino, E.M., Falceta-Gonçalves, D.A., Nakwacki, M.S., Kowal, G.
Formato:	JOUR
Materias:	Galaxies: clusters: intracluster medium Magnetic fields Methods: numerical Turbulence
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_00358711_v465_n4_p4866_SantosLima
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_00358711_v465_n4_p4866_SantosLima
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spelling	todo:paper_00358711_v465_n4_p4866_SantosLima2023-10-03T14:47:19Z Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback Santos-Lima, R. de Gouveia Dal Pino, E.M. Falceta-Gonçalves, D.A. Nakwacki, M.S. Kowal, G. Galaxies: clusters: intracluster medium Magnetic fields Methods: numerical Turbulence Statistical analysis of Faraday rotation measure (RM) maps of the intracluster medium (ICM) of galaxy clusters provides a unique tool to evaluate some spatial features of the magnetic fields there. Its combination with numerical simulations of magnetohydrodynamic (MHD) turbulence allows the diagnosis of the ICM turbulence. Being the ICM plasma weakly collisional, the thermal velocity distribution of the particles naturally develops anisotropies as a consequence of the large-scale motions and the conservation of the magnetic moment of the charged particles. A previous study (Paper I) analysed the impact of large-scale thermal anisotropy on the statistics of RM maps synthesized from simulations of turbulence; these simulations employed a collisionless MHD model that considered a tensor pressure with uniform anisotropy. In this work, we extend that analysis to a collisionless MHD model in which the thermal anisotropy develops according to the conservation of the magnetic moment of the thermal particles. We also consider the effect of anisotropy relaxation caused by the microscale mirror and firehose instabilities. We show that if the relaxation rate is fast enough to keep the anisotropy limited by the threshold values of the instabilities, the dispersion and power spectrum of the RM maps are indistinguishable from those obtained from collisional MHD. Otherwise, there is a reduction in the dispersion and steepening of the power spectrum of the RM maps (compared to the collisional case). Considering the first scenario, the use of collisional MHD simulations for modelling the RM statistics in the ICM becomes better justified. © 2016 The Authors. Fil:Nakwacki, M.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00358711_v465_n4_p4866_SantosLima
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Galaxies: clusters: intracluster medium Magnetic fields Methods: numerical Turbulence
spellingShingle	Galaxies: clusters: intracluster medium Magnetic fields Methods: numerical Turbulence Santos-Lima, R. de Gouveia Dal Pino, E.M. Falceta-Gonçalves, D.A. Nakwacki, M.S. Kowal, G. Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback
topic_facet	Galaxies: clusters: intracluster medium Magnetic fields Methods: numerical Turbulence
description	Statistical analysis of Faraday rotation measure (RM) maps of the intracluster medium (ICM) of galaxy clusters provides a unique tool to evaluate some spatial features of the magnetic fields there. Its combination with numerical simulations of magnetohydrodynamic (MHD) turbulence allows the diagnosis of the ICM turbulence. Being the ICM plasma weakly collisional, the thermal velocity distribution of the particles naturally develops anisotropies as a consequence of the large-scale motions and the conservation of the magnetic moment of the charged particles. A previous study (Paper I) analysed the impact of large-scale thermal anisotropy on the statistics of RM maps synthesized from simulations of turbulence; these simulations employed a collisionless MHD model that considered a tensor pressure with uniform anisotropy. In this work, we extend that analysis to a collisionless MHD model in which the thermal anisotropy develops according to the conservation of the magnetic moment of the thermal particles. We also consider the effect of anisotropy relaxation caused by the microscale mirror and firehose instabilities. We show that if the relaxation rate is fast enough to keep the anisotropy limited by the threshold values of the instabilities, the dispersion and power spectrum of the RM maps are indistinguishable from those obtained from collisional MHD. Otherwise, there is a reduction in the dispersion and steepening of the power spectrum of the RM maps (compared to the collisional case). Considering the first scenario, the use of collisional MHD simulations for modelling the RM statistics in the ICM becomes better justified. © 2016 The Authors.
format	JOUR
author	Santos-Lima, R. de Gouveia Dal Pino, E.M. Falceta-Gonçalves, D.A. Nakwacki, M.S. Kowal, G.
author_facet	Santos-Lima, R. de Gouveia Dal Pino, E.M. Falceta-Gonçalves, D.A. Nakwacki, M.S. Kowal, G.
author_sort	Santos-Lima, R.
title	Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback
title_short	Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback
title_full	Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback
title_fullStr	Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback
title_full_unstemmed	Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback
title_sort	features of collisionless turbulence in the intracluster medium from simulated faraday rotation maps - ii. the effects of instabilities feedback
url	http://hdl.handle.net/20.500.12110/paper_00358711_v465_n4_p4866_SantosLima
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Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback

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