Extracting Spectral Index of Intergalactic Magnetic Field from Radio Polarizations

TL;DR

This paper derives the spectral index of intergalactic magnetic fields from radio polarization correlations, finding strong agreement with cosmological simulations, and discusses physical scenarios for polarization alignment.

Contribution

It introduces a method to extract the magnetic field spectral index from radio polarization data, aligning observational results with simulation predictions.

Findings

Spectral index of -2.74 ± 0.04 for intergalactic magnetic fields.

Radio polarization correlations reflect magnetic field spatial correlations.

Agreement with cosmological magneto-hydrodynamic simulation results.

Abstract

We explain the large scale correlations in radio polarization in terms of the correlations of galaxy cluster/supercluster magnetic field. Assuming that the polarization correlations closely follow the spatial correlations of the background magnetic field we recover the magnetic field spectral index as -2.74$\pm$0.04.This remarkably agrees with cluster magnetic field spectral index obtained in cosmological magneto-hydrodynamic simulations. We discuss possible physical scenarios in which the observed polarization alignment is plausible.