The nature of the First Stars: the point of view of the neutron capture elements
by
Gabriele Cescutti(AIP Potsdam, DE)
→
Europe/Rome
Description
ABSTRACT: In the last years our group has found that many chemical anomalies observed in very metal-poor halo stars in the light elements suggest the first stellar generations to have been fast rotators (spinstars). Recently, theoretical computations have found that spinstars can also play a role in the chemical enrichment of neutron capture elements providing a early contribution of s-process. By means of a stochastic chemical evolution model, it is possible to identify the spinstars s-process contribution as the missing component responsible for the spread in the ratio between light (Sr) to heavy (Ba) neutron capture elements. A specific distribution is predicted for the isotopic ratio of Ba in halo stars and this imprint could be the smoking gun of the role played by spinstars in the spread of [Sr/Ba] ratio. In this context, regarding the still unknown origin of
the complementary r-process component, three possible sites are tested: the neutron star mergers, the electron capture supernovae and the magneto rotational driven supenovae; only further investigations in different Galactic component, as the bulge, will enable us to constrain the real site.
