Determine the magnetic field orientation and strength in G321.3–3.9

Determine the orientation of the plane-of-sky magnetic field vectors and the magnetic field strength within the supernova remnant G321.3–3.9 by acquiring and analyzing multi-frequency radio polarization data (including Stokes Q and U) to correct for Faraday rotation and derive reliable magnetic field measurements, as single-frequency S-PASS data do not permit such determination.

Background

The authors examined Stokes Q and U polarization images from S-PASS to assess linear polarization within G321.3–3.9 and identified a polarized region coincident with the shell. They computed a total polarization fraction of approximately 15%.

However, Faraday rotation at low radio frequencies alters the observed electric field orientation, and robust determination of magnetic field vectors and strength requires multi-frequency data. With only single-frequency S-PASS observations available, the authors could not derive the magnetic field vectors or strength in the remnant.