Title: Diffuse steep-spectrum sources from the 74 MHz VLSS survey
Abstract: Context. Galaxy clusters grow by a sequence of mergers with other clusters and galaxy groups. During these mergers, shocks and/or turbulence are created within the intracluster medium (ICM). In this process, particles could be accelerated to highly relativistic energies. The synchrotron radiation from these particles is observed in the form of radio relics and halos that are generally characterized by a steep radio spectral index. Shocks can also revive fossil radio plasma from a previous episode of AGN activity, creating a so-called radio “phoenix”. Here we present multi-frequency radio observations of diffuse steep-spectrum radio sources selected from the 74 MHz VLSS survey. Previous Giant Metrewave Radio Telescope (GMRT) observations showed that some of these sources had filamentary and elongated morphologies, which are expected for radio relics.