The primary goal of my EU-funded project ELEMENTS is to provide stringent observational constraints on the cosmic origins of elements heavier than iron and on the role of extreme objects in the evolution of the Milky Way.  This project represents the first systematic study of s-, p- and r-process nucleosynthesis across the entire Galaxy. 

We will use abundances of rare 
trans-Fe group elements for > 300.000 stars from 4MIDABLE-HR, the high-resolution spectroscopic survey of the disk and bulge on the 4MOST instrument.

Detailed theoretical models suggest that these chemical elements trace nucleosynthesis in a variety of extreme astrophysical sites: hydrostatic and explosive burning, s-process in asymptotic giant branch stars and in massive stars, r-process in compact binary mergers (neutron star mergers, NS-BH mergers), neutrino-driven winds of core collapse supernovae, magnetars, and collapsars.

The unprecendeted quality of the data will be achieved by using our know-how, Non-LTE models of stellar spectra with 3D convective atmospheres. We will quantify the trends of abundance ratios and their dispersions with metallicity, age, and location in the Galaxy. 

Contrasting these data with the predictions of chemical evolution models will allow us to constrain the multimodality of nuclear production sites, to confine the parameter space of stellar sources capable of hosting s- and r-process, and to make firm statements about the role extreme events in the evolution of our home Galaxy. 

Figure credit
(c) M. Bergemann, ESO/Y. Beletsky, G. Stinson

© Maria Bergemann 2022