Fields and Filaments in the Core of the Centaurus Cluster

We present high resolution images of the Faraday Rotation Measure (RM) structure of the radio galaxy PKS1246-410 at the center of the Centaurus cluster. Comparison with Hα-line and soft X-ray emission reveals a correspondence between the line-emitting gas, the soft X-ray emitting gas, regions with an excess in the RM images, and signs of depolarization. Magnetic field strengths of 25 μG, organized on scales of ∼1 kpc, and intermixed with gas at a temperature of 5 ×10 K with a density of ∼0.1 cm can reproduce the observed RM excess, the depolarization, and the observed X-ray surface brightness. This hot gas may be in pressure equilibrium with the optical line-emitting gas, but the magnetic field strength of 25 μG associated with the hot gas provides only 10% of the thermal pressure and is therefore insufficient to account for the stability of the line-emitting filaments.