High-frequency radio polarization measurements of WMAP point sources

TL;DR

This paper reports high-frequency polarization measurements of extragalactic radio sources to aid in foreground subtraction for future CMB experiments, providing essential data on source polarization properties at GHz frequencies.

Contribution

It provides new polarization measurements at 8.4, 22, and 43 GHz for a complete sample of bright extragalactic sources, aiding in understanding their impact on CMB observations.

Findings

Measurements are consistent with previous VLA calibration data.

Polarization properties are similar to WMAP fluxes for unresolved sources.

Data will support future analysis of foreground contamination in CMB studies.

Abstract

We present polarization measurements at 8.4, 22, and 43 GHz made with the VLA of a complete sample of extragalactic sources stronger than 1 Jy in the 5-year WMAP catalogue and with declinations north of -34 degrees. The observations were motivated by the need to know the polarization properties of radio sources at frequencies of tens of GHz in order to subtract polarized foregrounds for future sensitive Cosmic Microwave Background (CMB) experiments. The total intensity and polarization measurements are generally consistent with comparable VLA calibration measurements for less-variable sources, and within a similar range to WMAP fluxes for unresolved sources. A further paper will present correlations between measured parameters and derive implications for CMB measurements.