THE 13C-POCKET STRUCTURE IN AGB MODELS: CONSTRAINTS FROM ZIRCONIUM ISOTOPE ABUNDANCES IN SINGLE MAINSTREAM SiC GRAINS

被引：36

作者：

Liu, Nan ^{[1
,2
,3
]}

Gallino, Roberto ^{[4
]}

Bisterzo, Sara ^{[4
,5
]}

Davis, Andrew M. ^{[1
,2
,6
]}

Savina, Michael R. ^{[2
,3
]}

Pellin, Michael J. ^{[1
,2
,3
,6
]}

机构：

[1] Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA

[2] Chicago Ctr Cosmochem, Chicago, IL 60637 USA

[3] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA

[4] Univ Torino, Dipartimento Fis, I-10125 Turin, Italy

[5] INAF Osservatorio Astrofis Torino, I-10025 Pino Torinese, Italy

[6] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA

来源：

ASTROPHYSICAL JOURNAL | 2014年 / 788卷 / 02期

关键词：

circumstellar matter; meteorites; meteors; meteoroids; nuclear reactions; nucleosynthesis; abundances; stars: abundances; stars: AGB and post-AGB; GIANT BRANCH STARS; S-PROCESS NUCLEOSYNTHESIS; SILICON-CARBIDE GRAINS; CAPTURE CROSS-SECTIONS; LOW-METALLICITY STARS; NEUTRON-CAPTURE; STELLAR MODELS; REACTION-RATES; EVOLUTION; METEORITES;

D O I：

10.1088/0004-637X/788/2/163

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present postprocess asymptotic giant branch (AGB) nucleosynthesis models with different C-13- pocket internal structures to better explain zirconium isotope measurements in mainstream presolar SiC grains by Nicolussi et al. and Barzyk et al. We show that higher-than-solar Zr-92/Zr-94 ratios can be predicted by adopting a C-13- pocket with a flat C-13 profile, instead of the previous decreasing-with-depth C-13 profile. The improved agreement between grain data for zirconium isotopes and AGB models provides additional support for a recent proposal of a flat C-13 profile based on barium isotopes in mainstream SiC grains by Liu et al.

引用

页数：7