Open AccessVLA polarimetry observations of PKS 2322−123: estimating magnetic fields in the Abell 2597 cluster
Author(s) -
Pollack L. K.,
Taylor G. B.,
Allen S. W.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.08984.x
Subject(s) - physics , astrophysics , faraday effect , line of sight , spectral index , polarimetry , cluster (spacecraft) , astronomy , flux (metallurgy) , magnetic field , spectral line , scattering , optics , materials science , metallurgy , programming language , quantum mechanics , computer science
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 centre of the cooling‐core cluster Abell 2597. The inner X‐ray structure, the radio morphology and the steep spectral index (α=−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 −2 over this region. Based on these observations and Chandra X‐ray data, we suggest that the southern lobe has been deflected from its original south‐western orientation to the south and into our line of sight. Using the observed rotation measures (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 μG .