280560 VU The Cosmic Chemical Evolution (2024W)

From our present-day understanding of the Big Bang cosmochemistry after 1000 sec only H, He, and extremely small fractions ofthe next lighter elements, like Li, were produced. The further production of heavier elements by means of stellar processes is responsible for the present-day element abundances. Since the distribution of elements within galaxies and over the intergalactic space, called the COSMIC CHEMICAL EVOLUTION (CCE), can nowadays quite well be traced with cosmic time, its study is of paramount relevance and serves as fundamental cornerstone of the evolution of the universe and its structures.
By means of stellar evolutionary models the nucleosynthesis of elements can be understood. Their release by various stellar mass-loss processes on different timescales enrich the interstellar medium (ISM) in its gas phases differently by these elements and, by this, the next stellar populations. Spectral observations of stars of different ages e.g. within the Mikly Way and in galaxies of variuos masses allow insights into timescales and amounts of element enrichments and thus into the evolution of stellar and gaseous components. In addition, the observed ISM provides the actual chemical state which; however, is affected by gasdynamical effects.
Based on simple chemical evolutionary recipes, that include the so-called element yields, observational signatures of element abundances and abundance ratios will be studied and differences between galaxies compared with advanced chemo-dynamical evolutionary models. Not only cosmological simulations of structure formation and galaxy morphologies have to be validated with regard to the CCE, but also outliers from general relations, as e.g. the large element enrichment in the very early galaxies, must be understood.

The lecture will be held in English.