Galactic Chemical Evolution: the Impact of the 13C-pocket Structure on the s-process Distribution

TL;DR

This paper investigates how variations in the 13C-pocket structure within AGB stars influence the distribution of s-process elements in the Galaxy, using GCE models and observational data across different metallicities.

Contribution

It implements and extends previous studies by analyzing the impact of 13C-pocket uncertainties on Galactic chemical evolution predictions of s-process elements.

Findings

GCE predictions align with observed neutron-capture element trends.

Different 13C-pocket models can reproduce average Galactic s-process evolution.

Additional contributions from fast-rotating massive stars are significant.

Abstract

The solar s-process abundances have been analyzed in the framework of a Galactic Chemical Evolution (GCE) model. The aim of this work is to implement the study by Bisterzo et al. (2014), who investigated the effect of one of the major uncertainties of asymptotic giant branch (AGB) yields, the internal structure of the 13C pocket. We present GCE predictions of s-process elements computed with additional tests in the light of the suggestions provided in recent publications. The analysis is extended to different metallicities, by comparing GCE results and updated spectroscopic observations of unevolved field stars. We verify that the GCE predictions obtained with different tests may represent, on average, the evolution of selected neutron-capture elements in the Galaxy. The impact of an additional weak s-process contribution from fast-rotating massive stars is also explored.