S18B0043abst
S18B0043
The chemical enrichment history of our Galaxy remains one of the major open questions in modern astronomy. In the coming era of large optical high-resolution spectroscopic surveys, neutron-capture elements will feature prominently. In this proposal we focus on the closely related questions (1) when does slow neutron-capture process nucleosynthesis (s-process) in the Galactic disk commence, and (2) how does the s-process enrichment timescale compare to iron enrichment by SNe Ia? Observational hints of a slower enrichment timescale for s-process elements cannot be confirmed due to the measurement errors and poor sample selection. We will overcome these limitations by carefully selecting 60 targets and applying our proven high-precision abundance measurement techniques. Moreover, we will focus on the abundance ratios [s/Eu] and [alpha/Fe], of which the former is sensitive to s-process contributions and the latter is sensitive to SNe Ia contributions, to sharply catch the onset of those two enrichments. Our proposed high-precision abundance measurements will be remain valuable even in the era of large spectropscopic surveys, ensure Japanese leadership in this field and refine Galactic chemical evolution models.
This document was translated from LATEX by HEVEA.