A New Radio-X-Ray Probe of Galaxy Cluster Magnetic Fields

摘要: Results are presented of a new VLA-ROSAT study that probes the magnetic field strength and distribution over sample 16 "normal" low-redshift (z ≤ 0.1) galaxy clusters. The clusters span 2 orders magnitude in X-ray luminosity were selected to be free (unusual) strong radio cluster halos widespread cooling flows. Consistent with these criteria, most show relaxed morphology little or no evidence recent merger activity. Analysis rotation measure (RM) data shows cluster-generated Faraday RM excess out ~0.5 h Mpc from centers. results, combined imaging cluster-embedded sources ROSAT profiles, indicate hot intergalactic gas within is permeated high filling factor by fields at levels icm = 5-10(l/10 kpc)-1/2 μG, where l correlation length. These results lead global estimate total energy give insight into ultimate origin, which likely gravitational. also shed some light on evolutionary conditions existed onset