Conveners
Stellar Nucleosynthesis
- Paolo Ventura (Istituto Nazionale di Fisica Nucleare)
Stellar Nucleosynthesis
- Paolo Ventura (Istituto Nazionale di Fisica Nucleare)
Asymptotic giant branch stars (AGB) represent an important phase in stellar evolution, because of the important physical processes involved in describing their internal structure and evolution. About half of the heavy elements beyond iron were produced during their peculiar evolutionary phases. Furthermore, the diversity of the nuclear processes determining the nucleosynthesis in these stars...
Asymptotic Giant Branch (AGB) stars play a key role in the chemical evolution of galaxies. These stars are the fundamental stellar site for the production of light elements such as C, N and F, and half of the elements heavier than Fe via the slow neutron capture process ($s$-process). Hence, detailed computational models of AGB stars’ evolution and nucleosynthesis are essential for...
The observed evolutionary decrease of the $^{12}$C/$^{13}$C isotopic ratio,
Li and C abundances, accompanied by the increase of the N
abundance, in low-mass stars on the upper RGB is caused by
extra mixing in their radiative zones. Multi-dimensional
hydrodynamic simulations of thermohaline convection have
demonstrated that its rate of mixing is almost two orders of
magnitude as low as...
Asymptotic giant branch stars are major sources of heavy elements in the Universe.
Despite the huge progress made in the last decades in the theoretical modeling of these objects, mixing processes occurring in their interiors are quite uncertain, especially the physical mechanism leading to the formation of the $^{13}$C pocket. Here, I will present recent results from the new generation of...
The Barium (Ba) star phenomenon is unmissable from the study and understanding of nucleosynthetic processes occuring in AGB stars. Ba stars belong to binary systems, where the former AGB polluted the companion, a less evolved star, which became enriched with material produced through the slow neutron capture process (s process). While the AGB has evolved to a white dwarf, the currently...
The use of machine learning techniques in astronomy is becoming more and more widespread. Here I present our results on using machine learning (ML) methods for the comparison of observed Barium (Ba) star abundances and the predictions of AGB nucleosynthesis codes. This way, we can provide an estimate of the progenitor mass and metallicity of the former polluter AGB star that in the past...
Despite considerable progresses over the past few decades, the origin of trans-iron elements is not yet fully understood. In addition to the slow (s) and rapid (r) neutron capture processes, an intermediate neutron capture process (i-process) is thought to exist at neutron densities intermediate between the s- and r-processes. The existence of this process is supported by the observation of...
In the last years observations of Fe-poor stars have made possible to have detailed measurements of their surface chemical composition. These objects are the perfect laboratories in which is possible to investigate the differences among the possible astrophysical sites of element production, from the lightest ones to the neutron capture elements. In fact, iron poor stars probably formed during...
