First Steps in the Chemical Evolution of the Universe, Prof. Michael Wiescher


Location: zoom

CINA+COSNAP Colloquium, Beijing

First Steps in the Chemical Evolution of the Universe

Prof. Michael Wiescher
University of Notre Dame

7am Eastern time, 7pm Beijing time

The chemical evolution of the universe is dictated by nucleosynthesis processes in multiple generations of stars as the cauldrons of the cosmos. The first generation of stars burn on the ashes of the Big Bang, the primordial abundances of hydrogen, helium and a bit of lithium. The chemical analysis of the eldest observed stars, however, shows a pronounced abundance distribution between carbon, oxygen up to calcium with a few scattered observations of Fe, Ti, and Sr. The reaction chains bridging the mass gap of instability at A=5 and A=8 isotopes and feeding the CNO range, rely on the alpha cluster configuration of light nuclei. Several possible nucleosynthesis patterns will be discussed that facilitate further processing of CNO isotopes up to the Ca-Fe range. These first steps in the chemical evolution of the universe will be presented in the context of new experimental data, which provide new insight in the complex and highly dynamic nucleosynthesis environment of first stars.