The $^{13}C$-pockets in AGB Stars and Their Fingerprints in Mainstream SiC Grains

TL;DR

This study uses isotopic tracers in presolar SiC grains to constrain the $^{13}C$-pocket in AGB stars, revealing multiple mixing processes in their formation.

Contribution

It introduces three isotopic tracers to analyze $^{13}C$-pockets and correlates isotopic ratios in grains with AGB model calculations, highlighting multiple mixing processes.

Findings

Isotopic ratios of Sr and Ba in grains match models with large $^{13}C$-pockets.

Multiple mixing processes likely contributed to $^{13}C$-pocket formation.

Postprocess AGB models explain the observed isotopic data.

Abstract

We identify three isotopic tracers that can be used to constrain the $^{13}C$-pocket and show the correlated isotopic ratios of Sr and Ba in single mainstream presolar SiC grains. These newly measured data can be explained by postprocess AGB model calculations with large $^{13}C$-pockets with a range of relatively low $^{13}C$ concentrations, which may suggest that multiple mixing processes contributed to the $^{13}C$-pocket formation in parent AGB stars.