Atomära processer i stjärnatmosfärer: vägen till exakta grundämneshalter för galaktisk arkeologi
Tidsperiod: 2017-01-01 till 2020-12-31
Projektledare: Paul Barklem
Budget: 3 200 000 SEK
The measurement of stellar chemical abundancesis a fundamental problem in astrophysics. While spectral lines are routinely measured at accuracies of 1%, systematic errors dominate interpretation and errors in abundances are at least an order of magnitude larger. It can be reasonably expected, and evidence supports, that nature has more information to reveal if more accurate abundances are obtained. This project particularly examines the role of atomic processes involving hydrogen atoms, the simplest and most common element in the universe, on the stellar spectral lines of elements of interest and thus on the chemical abundance measured. This project will provide quantum mechanical calculations for inelastic collisions processes on many atoms of astrophysical importance using a novel method developed recently, thus solving a problem that has plagued a generation of stellar spectroscopists, and providing a significant legacy to stellar spectroscopy. With the advent of grids of 3D and non-LTE models, these advances will lead to improved accuracy in the measurement of stellar abundances. When coupled with the accurate stellar astrometry from Gaia and forthcoming large spectroscopic surveys such as 4MOST, this will open a new era of high-precisiongalactic archeology and inform our understanding of how the Milky Way and galaxies in general form. Accurate modelling of stellar spectra will also impact other fields, such as the study of exoplanets and stellar physics in general.