The Largest Shocks in the Universe: Insights from Observations
Kamlesh Rajpurohit (Harvard-CFA)
Tuesday 08/10/2024 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
Galaxy clusters undergoing major mergers host spectacular megaparsec-scale diffuse radio sources called radio relics. They are believed to originate from cosmic-ray electrons which are (re-)accelerated by merger-driven shocks in the intracluster medium (ICM). The origin of these CRe has been an outstanding problem in cluster physics for the past two decades, leaving our description of the physics of low-density ICM incomplete. There is increasing observational evidence that requires us to consider acceleration processes across the entire lifetime of clusters, not only in the proximity of large merger events. The new generation of radio telescopes permit wideband observations with unprecedented sensitivity and spatial resolution, allowing the investigation of the finest details. In this talk, I will discuss recent results obtained with high-resolution radio observations and open issues in this field.