Planetary Nebulae as Narrators of Stellar and Galactic Chemical Evolution: A New Probe of Galactochronology

这个项目专注于行星星云(PNE)化学丰度的光谱测定，以追踪银河系的化学演化和恒星核合成的产额。这项研究的目标包括：(1)得出硫(S)和Ar(Ar)在银河系盘面上的径向梯度；(2)调查S和Ar可作为恒星金属丰度研究中铁的示踪剂的假设；(3)确定PNE中央恒星的金属度；(4)使用所隐含的金属丰度来测试中等质量恒星核处理的理论产额；以及(5)测试单个PNE内已报道的丰度梯度。这项研究的一些数据已经收集完毕。如有需要，将在阿帕奇点天文台和其他地方获得新的高分辨率光谱数据。

ABSTRACTAST-9819123Kwitter, KarenThis project focuses on the spectroscopic determination of chemical abundances for planetary nebulae (PNe) as tracers of the chemical evolution of the Galaxy and yields of stellar nucleosynthesis. The objectives of the study include: (1) deriving the radial gradients of sulfur (S) and argon (Ar) across the disk of the Galaxy; (2) investigating the hypothesis that S and Ar can be used as tracers of Fe in stellar metallicity studies; (3) determination of the metallicity of the central star of PNe; (4) using the metallicities implied to test theoretical yields of nuclear processing in intermediate-mass stars; and (5) testing the reported abundance gradients within individual PNe. Some of the data for this study has already been collected. New high-resolution spectroscopic data will be obtained at the Apache Point Observatory and elsewhere, as required.