Evolution of the Distribution of Neutron Exposures in the Galaxy Disc: An Analytical Model

Journal of astrophysics and astronomy

Weijuan Zhang¹  Wenyuan Cui1 2¹  Bo Zhang1 2¹ 

[1]Department of Physics, Hebei Normal University, Shijiazhuang 050 016, P. R. China.$$

关键词: Nucleosynthesis;    neutron exposures;    abundances;    stars: AGB stars: low-mass stars;    galaxy: evolution.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

In this work, based on the analytical model with delayed production approximation developed by Pagel & Tautvaišienė (1995) for the Galaxy, the analytic solutions of the distribution of neutron exposures of the Galaxy (hereafter NEG) are obtained. The present results appear to reasonably reproduce the distribution of neutron exposures of the solar system (hereafter NES). The strong component and the main component of the NES are built up in different epochs. Firstly, the strong component is produced by the s-process nucleosynthesis in the metal-poor AGB stars, starting from [Fe/H] ≈ -1.16 to [Fe/H] ≈ -0.66, corresponding to the time interval 1.06 < 𝑡 < 2.6 Gyr. Secondly, the main component is produced by the s-process in the galactic disk AGB stars, starting from [Fe/H] ≈ -0.66 to [Fe/H] ≈ 0, corresponding to the time interval 𝑡 > 2.6 Gyr. The analytic solutions have the advantage of an understanding of the structure and the properties of the NEG. The NEG is believed to be an effective tool to study the s-process element abundance distributions in the Galaxy at different epochs and the galactic chemical evolution of the neutron-capture elements.

【 授权许可】

Unknown