Oxygen isotopic ratios in RGB & AGB stars

8th European Summer School on Experimental Nuclear Astrophysics (Santa Tecla School)

物理学;天文学

Halabi, Ghina M.^1,2 ; El Eid, Mounib^2

Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge

CB3 0HA, United Kingdom^1

American University of Beirut, Bliss Street 11-0236, Beirut

1107 2020, Lebanon^2

关键词: AGB stars;    Capture reaction;    Convective mixing;    Initial composition;    Low-mass stars;    Oxygen isotopic;    Schwarzschild criterion;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/703/1/012019/pdf
DOI  :  10.1088/1742-6596/703/1/012019

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

Stars in the mass range 1.2-7Mo, with solar-like initial composition are evolved from the zero age main sequence till the early AGB phase. Their predicted oxygen isotopic ratios are compared to observationally inferred values in red giants to investigate how well standard evolutionary calculation reproduces available observations and to illustrate the role of convective mixing. We find that extra mixing beyond the convective boundary determined by the Schwarzschild criterion is needed to explain the observational oxygen isotopic ratios, particularly in low mass stars. The effect of recent determinations of proton capture reactions and their uncertainties on16O/17O is also shown.