Colloquium by Jan Cami, Western University, Canada
Evolved stars, and planetary nebulae in particular, play a crucial role in shaping the chemical composition of the galaxy. These environments act as factories for the production and dispersal of complex molecules into the interstellar medium. Despite their importance, the origins of the remarkable chemical complexity observed in evolved star environments remain poorly understood. The James Webb Space Telescope (JWST) is revolutionizing our knowledge of the key physical and chemical processes in these dynamic regions. This talk will show how spatially resolved spectroscopic measurements of various molecules provide fundamentally new insights into the intricate interplay between physics and chemistry, and into the rich inventory of molecular species these environments contribute to the interstellar medium.
Fullerenes are a particularly interesting class of molecules in this context. These large, aromatic carbon molecules are “PAtHfinder” species, offering unique insights into the processes affecting other aromatic compounds, such as polycyclic aromatic hydrocarbons (PAHs). Their formation, excitation mechanisms, and evolutionary pathways remain enigmatic, but they serve as critical probes for understanding the broader evolution of large carbonaceous materials in planetary nebulae. A comprehensive study of the planetary nebula Tc 1, using imaging and spectroscopic observations from different observatories and instruments, is gradually revealing its secrets, shedding light on the conditions and processes that govern fullerene chemistry and, by extension, the chemistry of other carbonaceous species.
Followed by wine and cheese.
Host: Daniel Wolf Savin