Evolution of shock waves and associated type II radio emission in the low corona and interplanetary space

摘要: Type II radio bursts are generally observed in association with flare-generated or CME-driven (coronal mass ejection) shock waves. They are signatures of fast electron beams which are accelerated at the shock front. The exact shock and coronal conditions necessary for the production of the type II radio emission are still debated. The preferred location of the type II radio sources on the surface of the shock wave, can either be at regions close to the CME/shock leading edge or at the CME/shock flanks, or both, and has been a long-standing discussion. We address this question in a twofold study: In Kouloumvakos et al.(2021), we study a coronal shock wave associated with a multi-lane metric type II on 05 November 2014 and in Jebaraj et al.(2021), we study a shock wave associated with a flare/CME event and a complex radio event on September 27, 2012. In these studies, we employ a novel approach, combining …