Speaker: Hiroko Okada<\/p>\n\n\n\n
Abstract:<\/p>\n\n\n\n
The origin of the rapid neutron-capture process is a major question in astrophysics. The clue to answer this question is the chemical abundance patterns of metal-poor stars, which are believed to reflect the nucleosynthesis yields of a single event. Recent observations propose two r-process classes: the “main r-process” for light and heavy elements and the “weak r-process” for lighter ones. Aoki et al. (2017) suggested to use abundance ratios of first-peak neutron-capture elements (Sr-Ag) in metal-poor stars to identify the origin of weak r-process nucleosynthesis. However, their sample is not necessarily extremely metal-poor, and some contamination of main r-process, and even s-process, is suspected. To clarify the weak r-process’s pure abundance pattern, we studied the extremely metal-poor star SMSS J022423.27-573705.1, with a high lower limit on [Sr\/Ba] ratio (Jacobson et al., 2015). Analyzing near UV spectrum data from the VLT\/UVES, we measured 26 elemental abundances including first-peak neutron-capture elements and determine Ba abundance. We also compare our results with the latest nucleosynthesis models.<\/p>\n","protected":false},"excerpt":{"rendered":"