Extracting the spectral index of the intergalactic magnetic field from radio polarizations

Abstract

We explain the large-scale correlations in radio polarization in terms of the correlations of the galaxy supercluster magnetic field. Assuming that the polarization correlations closely follow the spatial correlations of the background magnetic field, we obtain the magnetic field spectral index as -2.74 ± 0.04. We discuss the possible physical scenarios in which the observed polarization alignment is plausible.