VLA Polarimetry Observations of PKS 2322-123; Estimating Magnetic Fields in the Abell 2597 Cluster

Abstract

We present 5, 8, and 15 GHz total intensity and polarimetric observations of the radio source PKS 2322-123 taken with the Very Large Array (VLA). This small (11 kpc) source is located at the center of the cooling-core cluster Abell 2597. The inner X-ray structure, the radio morphology, and the steep spectral index (alpha = -1.8) in the lobes, all suggest that the radio emission is confined by the ambient X-ray gas. We detect a small region of polarized flux in the southern lobe and are able to calculate a Faraday rotation measure (RM) of 3620 rad/m/m over this region. Based on these observations and Chandra X-ray data we suggest that the southern lobe has been deflected from its original southwestern orientation to the south and into our line-of-sight. Using the observed RMs and our calculated electron density profiles, and assuming both a uniform and tangled magnetic field topology, we estimate a lower limit of the line-of-sight cluster magnetic field, B = 2.1 microgauss.