Description
Recent low-frequency radio observations have revealed a small sample of collimated synchrotron threads, or magnetic threads, in galaxy clusters. In particular, Ramatsoku et al. reported synchrotron threads connecting the radio lobes of ESO 137-006 using MeerKAT in 2020 and Rudnick et al. detected synchrotron threads extending away from the Northern radio lobe of 3C40B briefly thereafter. The current hypothesis is that these structures form when radio plasma emitted by an active galactic nucleus (AGN) interacts with the magnetic fields present in the cluster environment. Such collimated synchrotron threads then trace magnetic "tubes" embedded within the intracluster medium (ICM), which keeps the radio plasma contained and carries it away through the ICM. If this is the case, high-resolution low-frequency radio observations provide a unique opportunity to study the magnetic field structure within galaxy clusters by detecting and resolving these synchrotron threads. To test this potential dichotomy in the structure of radio lobes, I have compiled a sample of 24 bright nearby radio sources from the 3CR catalog which are either in a field environment or central cluster environment to test whether the presence of synchrotron threads is unique to cluster environments. Of the 24 sources, 20 are now imaged at sub-arcsecond resolution using LOFAR for the first time. In this talk, I will present the results of this analysis and discuss the implications on the nature of synchrotron threads.
