When Clusters Collide and Telescopes Misbehave: Low-frequency Polarization Properties of Radio Relics with uGMRT

Abstract: 

When galaxy clusters collide at thousands of kilometers per second, they create cosmic particle accelerators spanning millions of light years, driving shocks that accelerate particles and amplify magnetic fields to produce diffuse radio emissions revealing the invisible architecture of these extreme environments. I’ll present low-frequency polarization observations of merging galaxy clusters using the upgraded Giant Metrewave Radio Telescope (uGMRT), supported by X-ray and high-frequency radio data from VLA and MeerKAT. Surprisingly, we found that low-frequency polarization does not follow high-frequency predictions, with depolarization inconsistent with single-component magnetic field models. We present the first linear polarization detection below 1 GHz requiring multicomponent magnetic field distribution, challenging conventional shock compression models in radio relics.