Title: Electron-Ion Collision Studies for Recent Astronomical Observations from the Early Universe

Speaker: Reinhold Schuch, Physics Department, Stockholm University, Stockholm Sweden

Time: 10:00-12:00, Nov. 26 (Wednesday), 2025

Place: Lecture hall, Building 6 

Abstract:  

The charge state balance in a astrophysical plasma is governed by ionization (photoionization, electron-impact ionization)  and recombination processes, such as radiative recombination and dielectronic recombination, that also gives photon emission. In the talk previous and recent measurements of electron-impact ionization and recombination processes at the FAIR storage ring CRYRING are presented. Examples are selected that are relevant for the recent surprising observations with the  James Webb Space Telescope (JWST). Where in very young galaxies large abundances of ions are found indicating those as the very first elements created by nucleosynthesis in the nascent universe. This challenges the present galaxy formation models and the interpretation of observations from the early universe and motivates the electron-ion collision studies at the storage ring.