Linda Lombardo (University Frankfurt)

The rapid neutron capture process is responsible for the synthesis of roughly half of the elements heavier than Zn (Z>30) in the solar system, however, it is still unclear what the exact astrophysical sites of the r-process are, and if different r-process nucleosynthetic channels exist, particularly at low metallicities. Metal-poor stars play a key role in understanding the nucleosynthesis of heavy elements in the early Universe, as their chemical abundances reflects the composition of the gas in which they formed. These stars show a variety of heavy chemical abundances patterns, with extreme variation in the r- process elements, from [Eu/Fe] below solar to [Eu/Fe]>1 in r-rich stars. This large scatter in heavy elements abundances seems to suggest that more than one formation site is responsible for the nucleosynthesis of these elements, and/or that the formation happens under different physical conditions. Homogeneous surveys of high resolution and signal-to- noise ratio spectra are therefore essential for understanding the heavy elements formation, as they provide abundances that can be used to test nucleosynthesis models as well as Galactic chemical evolution models.

Presentation (pdf)