The polarimetric multi-frequency radio sources properties

TL;DR

This paper investigates the polarization properties of extragalactic radio sources at frequencies above 20 GHz, providing new observational data crucial for understanding emission physics and foreground contamination in CMB studies.

Contribution

It presents new multi-frequency polarization observations of 53 radio sources, highlighting the complexity of polarization behavior beyond total intensity spectra.

Findings

Polarization properties differ significantly from total intensity spectra.

Spectral behaviors of polarization and total intensity are typically different.

New observational data at 5.5-38 GHz for 53 sources.

Abstract

The polarization properties of extragalactic radio sources at frequencies higher than 20 GHz are still poorly constrained. However, their characterization would provide invaluable information about the physics of the emission processes and is crucial to estimate their contamination as foregrounds of the polarized cosmic microwave background (CMB) angular power spectrum on scales < 30 arcmin. In this contribution, after summarizing the state-of-the-art of polarimetric observations in the millimetric wavelength bands, we present our observations of a complete sample of 53 sources with S > 200 mJy (at 20 GHz) carried out with the Australia Telescope Compact Array between 5.5 and 38 GHz. The analysis clearly shows that polarization properties cannot be simply inferred from total intensity ones, as the spectral behaviors of the two signals are typically different.