VLA polarimetry of radio sources behind Perseus

Our survey covers ~13.8deg2 with a mean Stokes I sensitivity of ~80{mu}Jy/beam, enabling the detection of 1410 compact radio sources. From this population, we construct a catalog of source properties, including positions, integrated flux densities, and spectral indices measured across nine spectral windows.

The majority of sources exhibit negative spectral indices, consistent with nonthermal synchrotron emission. Using the rotation measure (RM)-based RM Synthesis and RM CLEAN techniques, we detect 205 polarized background sources above an 8{sigma} threshold. This corresponds to a sampling density of ~14.8deg^-2^, representing more than an order of magnitude increase compared to previous NVSS-based measurements.