Abstract Details

Name: Drisya Karinkuzhi
Affiliation: Indian Institute of Science, Bangalore
Conference ID: ASI2020_43
Title : Key nucleosynthesis diagnostics in Carbon-Enhanced Metal-Poor (CEMP)-r/s stars
Authors and Co-Authors : Drisya Karinkuzhi
Abstract Type : Invited
Abstract Category : Stars, ISM and Galaxy
Abstract : Low- and intermediate-mass stars (LIMS, M < 8M0) dominate the stellar populations in our Galaxy. During their ascent of the thermally-pulsing asymptotic giant branch (TP-AGB) phase, LIMS are the siege of a rich nucleosynthesis, forging mainly carbon and roughly half of the elements heavier than iron through the so-called s-process. Ejecting these elements at the end of their life, they play a major role in the chemical evolution of the Galaxy. Another key nucleosynthetic process, responsible for the production of the other half of the elements heavier than iron, is the r-process, operating at higher neutron densities. Its astrophysical site is yet unclear but recent analysis of the optical counterpart of the source of the gravitational wave event GW170817 revived the neutron-star mergers as a very plausible r-process site. In that framework, the origin of the peculiar chemical composition of r/s stars (stars enriched in both s- and r- process elements), mostly found among Carbon-Enhanced Metal-Poor stars and hence called CEMP-r/s stars, whose binarity has not been established yet, is completely unclear. Even though there are many scenarios invoked to explain their peculiar abundances, the intermediate-process (i-process), a process occurring at neutron densities intermediate between s- and r- processes, leads to an excellent match to the observed heavy-element abundance pattern in many CEMP-r/s stars, but the astrophysical site of this process is still under debate. In my talk, I will be discussing about the key nucloesynthesis diagnostics to understand and constrain the origin of peculiar abundance pattern in CEMP-r/s stars.