Speaker
Description
Among the diverse population of astrophysical transients, those powered by the interaction between explosive ejecta and circumstellar material (CSM) are of particular interest, not only as electromagnetic transients but also as potential sites of high-energy particle acceleration. Understanding how CSM interaction converts kinetic energy of the ejecta into electromagnetic radiation through detailed comparisons between theoretical models and observations is essential for constraining the conditions under which particle acceleration may occur. In this talk, I focus on core-collapse supernovae exploding within dense circumstellar environments and discuss recent efforts to model their electromagnetic emission using numerical simulations. Shock breakout marks the onset of observable emission and provides a unique probe of energy dissipation occurring at the interface between the outermost layers of the ejecta and the innermost regions of the CSM. Numerical modeling of shock breakout emission has played an important role in constraining both the ejecta structure and the properties of the surrounding CSM. I review the physical processes responsible for the early emission from interaction-powered transients, summarize recent developments in numerical modeling, and discuss implications from several recently observed events.
