A Comprehensive Catalog of Radio Sources and Rotation Measures in the Perseus Molecular Cloud from Very Large Array Observations

Abstract We present a comprehensive radio polarization study of the Perseus molecular cloud using wideband L -band observations from the Karl G. Jansky Very Large Array. Our survey covers ∼13.8 deg 2 with a mean Stokes I sensitivity of ∼80 μ Jy beam −1 , 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 σ threshold. This corresponds to a sampling density of ∼14.8 deg −2 , representing more than an order of magnitude increase compared to previous NVSS-based measurements. The resulting RMs exhibit coherent large-scale variations across the surveyed region, with additional small-scale structure superimposed. The enhanced sensitivity, frequency coverage, and sampling density of our observations enable a substantially improved mapping of the line-of-sight magnetic field component toward the Perseus molecular cloud compared to previous surveys.