Author(s): A. Williams, Macalester College, St Paul, Minnesota, UNITED STATES|A. Williams, E. Wilcots, E. Zweibel, University of Wisconsin-Madison, Madison, Wisconsin, UNITED STATES|
Institution(s): 1. Macalester College, St Paul, MN, United States. 2. University of Wisconsin-Madison, Madison, WI, United States.
Contributing team(s): (none)
We present the results of a study to observe magnetic fields within the intragroup medium of galaxy group NGC 2563. We use full polarization observations at S band (2-4 GHz) collected at the Karl G. Jansky Very Large Array to measure the polarization of extragalactic systems within 0.5 degrees of NGC 2563. Our survey detected 183 sources, 22 of which are at least 1% polarized. None of these polarized sources are associated with known group members, and determined to be background sources. We use the Faraday rotation of the polarized sources to probe the intragroup medium. When we compare the Faraday rotation of polarized sources with sightlines that pass within 420 kpc of the group center to those that pass through the outer 420 kpc, we see a slight increase in Faraday dispersion towards the center. This increase in Faraday dispersion follows the observed increase in electron density towards the center of the group, and is likely due to a combination of this property as well as an increase the magnetic field strength. Furthermore, we find that polarized sightlines that pass within 120 kpc of a known group member also show an increase in Faraday rotation dispersion, which may be due to magnetic field amplifciation via tidal interactions, ram pressure stripping, or turbulent wakes as the galaxies move through the intragroup medium. While this is the first study of its kind, we expect future all-sky surveys like the VLA Sky Survey will rapidly contribute to the detection of polarized sources towards galaxy groups and clusters. This will greatly improve our statistical understanding of the magnetized medium with large-scale galaxy structures, and help us to unravel the origin of large-scale magnetic fields in and around galaxies.