3:30–4:30 pm ERC 161
Title: Decoding the Origin of the Elements
Abstract: The elemental abundance patterns of stars encode a wealth of information about the history of the Milky Way galaxy and the astrophysical processes that create atomic nuclei. I will describe some of what we have learned about the origin of elements in the Milky Way from spectroscopic surveys, especially the SDSS APOGEE survey, which has measured detailed abundance patterns (typically 15-18 elements per star) for half a million stars.The median trends of element abundance ratios are nearly independent of location within the Galactic disk or bulge, and we can model these trends to separate the enrichment contributions of core collapse supernovae from those of time-delayed sources such as Type Ia supernovae or AGB stars. The enrichment pattern of core collapse supernovae can in turn test theoretical models of massive star evolution and black hole formation. Other elements such as nitrogen and cerium provide clues to the mixing of nuclear-processed material within intermediate mass stars. The most important degeneracy in Galactic chemical evolution models is the tradeoff between the overall yield of heavy elements (sensitive to black hole formation) and the ejection of elements in galactic winds; I will discuss approaches to breaking this degeneracy.
Zoom: https://uchicago.zoom.us/j/96426832251?pwd=sWlgab9U46NofRA0VMaC7Y1sLA99Te.1