Contact Name: Donatella Romano
Abstract:
The dominant production site of the r-process elements in galaxies has not yet been unambiguously identified. Neutrino-driven winds from proto-neutron stars following the delayed explosions of massive stars (m > 20 MSun) were suggested as a promising site, but soon ruled out because they are proton-rich, rather than neutron-rich as required. Prompt explosions of lower-mass stars (8-10 MSun), in principle, could eject substantial amounts of r-process matter, but it is not clear whether they do actually occur. Recent investigations suggest that highly-rotating massive stars with strong magnetic fields and compact binary mergers can synthesise substantial amounts of r-process elements. However, they are both rare. I will discuss the results we get by implementing these r-process factories in a detailed chemical evolution model for the Milky Way, and discuss pros and cons of each scenario.