Integrated Polarization of Sources at lambda ~1m and New Rotation Measure Ambiguities

Understand

We present an analysis of the polarization of compact radio sources from six pointings of the Westerbork Synthesis Radio Telescope (WSRT) at 350 MHz with 35% coverage in lambda^2.

• After correcting for the off-axis instrumental polarization with a simple analytical model, only a small number of 585 strong sources have significant polarizations at these wavelengths.
• The median depolarization ratio from 1.4 GHz for the strongest sources is <0.2, reinforcing the likelihood that radio galaxies are found in magnetized environments, even outside of rich clusters.
• Seven sources with significant 350 MHz polarization were selected for a more in-depth Faraday structure analysis.