Asplund, Martin

Contact Email: martin@astro.uu.se
Institute: Uppsala Astronomical Observatory
First Coauthor: Poul Erik Nissen
Institute: Institute of Physics and Astronomy, Aarhus
Second Coauthor: Francesca Primas
Institute: European Southern Observatory, Garching
Research URL:http://www.astro.uu.se/~martin
Subject Area: Stellar Atmospheres, Circumstellar Material
Waveband: Optical
Technique: Computational Astrophysics
Other: Stellar spectroscopy (cool stars)
Presentation: Poster Display
Title: The light elements in metal-poor halo stars
Abstract: The light elements (Li to O) function as sensitive probes of various physical processes in astrophysics and cosmology. We have investigated the line formation of the light elements by means of the new generation of realistic 3D hydrodynamical model atmospheres both for solar-type stars and metal-poor halo stars. The temperature inhomogeneities and different mean photospheric structures have a profound impact on the conclusions drawn from studies of the light elements, in particular for metal-poor stars. The 3D model atmospheres have been employed for an abundance analysis of Li (including 6Li), Be and O for a large sample of halo stars using high S/N and resolution VLT/UVES spectra. The results have direct bearings on Big Bang nucleosynthesis, cosmic ray spallation, galactic evolution and stellar mixing.