English

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

Astrophysics of Galaxies 2026-02-23 v1

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\sim13.8~deg2^2 with a mean Stokes~II sensitivity of 80 μ\sim80~\muJy~beam1^{-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 non-thermal synchrotron emission. Using RM Synthesis and RM CLEAN techniques, we detect 205 polarized background sources above an 8σ8\sigma threshold. This corresponds to a sampling density of 14.8\sim14.8~deg2^{-2}, representing more than an order-of-magnitude increase compared to previous NVSS-based measurements. The resulting rotation measures 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.

Keywords

Cite

@article{arxiv.2602.17980,
  title  = {A Comprehensive Catalog of Radio Sources and Rotation Measures in the Perseus Molecular Cloud from Very Large Array Observations},
  author = {Haleh Hajizadeh and Jeroen Stil and René Plume and Mehrnoosh Tahani and Preshanth Jagannathan},
  journal= {arXiv preprint arXiv:2602.17980},
  year   = {2026}
}