{ "id": "2011.02419", "version": "v1", "published": "2020-11-04T17:18:29.000Z", "updated": "2020-11-04T17:18:29.000Z", "title": "i-process nucleosynthesis: observational evidences from CEMP stars", "authors": [ "Partha Pratim Goswami", "Aruna Goswami" ], "comment": "8 pages, 2 figures, accepted for publication in Journal of Astrophysics and Astronomy (JAA)", "categories": [ "astro-ph.SR" ], "abstract": "The surface chemical compositions of a large fraction of Carbon-Enhanced Metal-Poor (CEMP) stars, the so-called CEMP-r/s stars, are known to exhibit enhancement of both s- and r-process elements. For these stars, the heavy element abundances cannot be explained either by s-process or r-process nucleosynthesis alone, as the production sites of s- and r-process elements are very different, and these two processes produce distinct abundance patterns. Thus, the observational evidence of the double enhancement seen in CEMP-r/s stars remains a puzzle as far as the origin of the elements is concerned. In this work, we have critically analysed the observed abundances of heavy elements in a sample of eight CEMP-r/s stars from literature, to trace the origin of the observed double enhancement. Towards this, we have conducted a parametric-model based analysis to delineate the contributions of s- and r-process nucleosynthesis to the observed elemental abundances. We have further examined if the i-process (intermediate process) nucleosynthesis, that occurs at a high neutron-density (n$\\sim$10$^{15}$ cm$^{-3}$ ) produced during proton-ingestion from a H-rich envelope to the intershell region of an AGB star, that is capable of producing both r- and s-process elements in a single stellar site, could explain the observed abundance patterns of the sample stars. Our analysis shows that the observed abundance patterns of the selected sample of CEMP-r/s stars could be fairly well reproduced using the i-process model yields.", "revisions": [ { "version": "v1", "updated": "2020-11-04T17:18:29.000Z" } ], "analyses": { "keywords": [ "observational evidence", "cemp stars", "i-process nucleosynthesis", "cemp-r/s stars", "processes produce distinct abundance patterns" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }