TAPIR Seminar

In person: 370 Cahill. To Join via Zoom: 868 5298 8404

ABSTRACT: The energy released by supernovae and accretion onto supermassive black holes plays a crucial role in galaxy formation and evolution. A significant portion of this feedback energy is carried by high-energy charged particles known as cosmic rays (CRs), which can influence galactic ecosystems by ionizing molecular clouds, heating galactic halos, and driving galactic winds. Accurately modeling these processes requires a detailed understanding of how CRs propagate through and interact with the interstellar medium (ISM). Despite decades of theoretical work and precise measurements of CR spectra, the physics of CR transport remains a major open problem. In this talk, I will present a new model of CR propagation based on scattering by rare, coherent structures embedded in the turbulent ISM. I will also argue that these same structures may be simultaneously responsible for another long-standing ISM mystery: extreme scattering events — dramatic fluctuations in the radio flux of compact radio sources lasting from weeks to years.