Properties of Polarized Synchrotron Emission from Fluctuation Dynamo Action -- II. Effects of Turbulence Driving in the ICM and Beam Smoothing

Abstract

Polarized synchrotron emission from the radio halos of diffuse intracluster medium (ICM) in galaxy clusters are yet to be observed. To investigate the expected polarization in the ICM, we use high resolution ($1$\,kpc) magnetohydrodynamic simulations of fluctuation dynamos, which produces intermittent magnetic field structures, for varying scales of turbulent driving ($l_{\mathrm{f}}$) to generate synthetic observations of the polarized emission. We focus on how the inferred diffuse polarized emission for different $l_{\mathrm{f}}$ is affected due to smoothing by a finite telescope resolution. The mean fractional polarization $⟨p⟩$ vary as $⟨p⟩\propto l_{\mathrm{f}}^{1/2}$ with $⟨p⟩>20\%$ for $l_{\mathrm{f}}\gtrsim 60$\,kpc, at frequencies $\nu >4\mathrm{GHz}$. Faraday depolarization at $\nu <3$\,GHz leads to deviation from this relation, and in combination with beam depolarization, filamentary polarized structures are completely erased, reducing $⟨p⟩$ to below 5\% level at $\nu \lesssim 1$\,GHz. Smoothing on scales up to $30$\,kpc reduces $⟨p⟩$ above $4$\,GHz by at most a factor of 2 compared to that expected at $1$\,kpc resolution of the simulations, especially for $l_{\mathrm{f}}\gtrsim 100$\,kpc, while at $\nu <3$\,GHz, $⟨p⟩$ is reduced by a factor of more than 5 for $l_{\mathrm{f}}\gtrsim 100$\,kpc, and by more than 10 for $l_{\mathrm{f}}\lesssim 100$\,kpc. Our results suggest that observational estimates of, or constrain on, $⟨p⟩$ at $\nu \gtrsim 4$\,GHz could be used as an indicator of the turbulent driving scale in the ICM.

arXiv comment22 pages, 8 figures, Accepted the Special Issue "A New Window on the Radio Emission from Galaxies, Galaxy Clusters and Cosmic Web: Current Status and Perspectives" of MDPI Galaxies

References in corpus (54)

• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Observational Evidence of AGN Feedback
• Astrophysical magnetic fields and nonlinear dynamo theory
• Faraday Rotation Measure Synthesis
• Clusters of galaxies : observational properties of the diffuse radio emission
• Cosmic rays in galaxy clusters and their non-thermal emission
• A New Radio - X-Ray Probe of Galaxy Cluster Magnetic Fields
• Simulations of small-scale turbulent dynamo
• Magnetic Field in Clusters of Galaxies
• Diffuse Radio Emission from Galaxy Clusters
• Turbulence and Magnetic Fields in the Large Scale Structure of the Universe
• The Coma cluster magnetic field from Faraday rotation measures
• Self-regulated growth of supermassive black holes by a dual jet/heating AGN feedback mechanism: methods, tests and implications for cosmological simulations
• Evolving turbulence and magnetic fields in galaxy clusters
• The Westerbork SINGS Survey II. Polarization, Faraday Rotation, and Magnetic Fields
• X-Ray surface brightness and gas density fluctuations in the Coma cluster
• Complex Faraday depth structure of Active Galactic Nuclei as revealed by broadband radio polarimetry
• The diffuse radio emission from the Coma cluster at 2.675 GHz and 4.85 GHz
• Cluster Magnetic Fields from Galactic Outflows
• Resolved magnetic dynamo action in the simulated intracluster medium
• Atmospheric gas dynamics in the Perseus cluster observed with Hitomi
• A2255: the First Detection of Filamentary Polarized Emission in a Radio Halo
• A thermally stable heating mechanism for the intracluster medium: turbulence, magnetic fields and plasma instabilities
• On the amplification of magnetic fields in cosmic filaments and galaxy clusters
• Turbulence and Vorticity in Galaxy Clusters Generated by Structure Formation
• AGN jet feedback on a moving mesh: cocoon inflation, gas flows and turbulence
• Revealing the magnetic field in a distant galaxy cluster: discovery of the complex radio emission from MACS J0717.5 +3745
• Vorticity, Shocks and Magnetic Fields in Subsonic, ICM-like Turbulence
• The Matryoshka Run (II): Time Dependent Turbulence Statistics, Stochastic Particle Acceleration and Microphysics Impact in a Massive Galaxy Cluster
• Fast Radio Bursts as Probes of Magnetic Fields in the Intergalactic Medium
• Fluctuation dynamos and their Faraday rotation signatures
• Characteristic Lengths of Magnetic Field in Magnetohydrodynamic Turbulence
• Suppressed effective viscosity in the bulk intergalactic plasma
• Cluster Turbulence
• Dynamical evolution of magnetic fields in the intracluster medium
• Suppression of electron thermal conduction in the high $\beta$ intracluster medium of galaxy clusters
• The Cosmic Large-Scale Structure in X-rays (CLASSIX) Cluster Survey I: Probing galaxy cluster magnetic fields with line of sight rotation measures
• The intergalactic magnetic field probed by a giant radio galaxy
• Relics in galaxy clusters at high radio frequencies
• Deep multi-frequency rotation measure tomography of the galaxy cluster A2255
• Physical insights from the spectrum of the radio halo in MACS J0717.5+3745
• Polarisation of Radio Relics in Galaxy Clusters
• A multiwavelength view of the galaxy cluster Abell 523 and its peculiar diffuse radio source
• The scaling relations and the fundamental plane for radio halos and relics of galaxy clusters
• Comparisons of Cosmological MHD Galaxy Cluster Simulations to Radio Observations
• Evolution of vorticity and enstrophy in the intracluster medium
• Faraday rotation signatures of fluctuation dynamos in young galaxies
• Troubled cosmic flows: turbulence, enstrophy and helicity from the assembly history of the intracluster medium
• Connecting turbulent velocities and magnetic fields in galaxy cluster simulations with active galactic nuclei jets
• The Magnetic Field and Polarization Properties of Radio Galaxies in Different Accretion States
• Suppression of local heat flux in a turbulent magnetized intracluster medium
• Decaying turbulence and magnetic fields in galaxy clusters

Cited by in corpus (4)

• Exploring diffuse radio emission in galaxy clusters and groups with the uGMRT and the SKA
• Role of magnetic pressure forces in fluctuation dynamo saturation
• Probing the Morphology of Polarized Emission Induced by Fluctuation Dynamo using Minkowski Functionals
• Radiative transfer of 21-cm line through ionised cavities in an expanding universe