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
[...] Read more.
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 (
) to generate synthetic observations of the polarized emission. We focus on how the inferred diffuse polarized emission for different
is affected due to smoothing by a finite telescope resolution. The mean fractional polarization
vary as
with
for
kpc, at frequencies
. Faraday depolarization at
GHz leads to deviation from this relation, and in combination with beam depolarization, filamentary polarized structures are completely erased, reducing
to below 5% level at
GHz. Smoothing on scales up to 30 kpc reduces
above 4 GHz by at most a factor of 2 compared to that expected at 1 kpc resolution of the simulations, especially for
kpc, while at
GHz,
is reduced by a factor of more than 5 for
kpc, and by more than 10 for
kpc. Our results suggest that observational estimates of, or constrain on,
at
GHz could be used as an indicator of the turbulent driving scale in the ICM.
Full article
