PHYS/ASTR Colloquium: "Nucleosynthesis at the isotopic level: magnesium isotope ratios in globular clusters" - Dr. Madeleine McKenzie (Hubble Fellow, Carnegie Observatories)

"Nucleosynthesis at the isotopic level: magnesium isotope ratios in globular clusters"

In the context of hierarchical galaxy assembly, old gravitationally bound collections of stars, known as globular clusters, serve as indispensable probes of the formation of our Milky Way. The chemical composition of stars within these ancient structures plays a pivotal role in constraining their chemical enrichment history. Globular clusters contain not one, but multiple populations of stars, each characterized by variations in elements such as carbon, nitrogen, sodium, and oxygen. To date, most studies have focused almost exclusively on elemental abundances; however, nucleosynthesis operates at the isotopic level. This talk will discuss how Mg isotope ratios shed light on the light element-enhanced populations within the anomalous globular cluster-like object M22. These measurements reveal contributions from supernovae and low-mass stars that cannot be discerned through elemental abundances alone.