Understanding the Nature and Environment of Ultra-Steep Spectrum Radio Relics

We propose followup observations of three galaxy clusters containingultrasteep spectrum (USS) radio relic sources that have existing lowfrequencyGMRT observations. Comparing the morphology and thermal structure of the ICM tothe diffuse radio emission will allow constraints to be placed on the nature ofthese relatively poorly studied sources. For example, a correlation betweenmerger shocks and radio emission implies direct shock acceleration, as withclassical radio relics, whereas a lack of correlation in a disturbed systemsuggests acceleration of an existing particle population by adiabaticcompression. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]