Detalles de publicación

PP 018027

Heavy-element yields and abundances of Asymptotic Giant Branch models with a Small Magellanic Cloud metallicity

Amanda Karakas (1), Maria Lugaro (2,1), Marília Carlos (1,3), Borbála Cseh (2), Devika Kamath (4,5), D. A. García-Hernández (6)
(1) Monash; (2) Konkoly Obs.; (3) Univ. Sao Paulo; (4) Mcquarie Univ; (5) AAO; (6) IAC-ULL
We present new theoretical stellar yields and surface abundances for asymptotic giant branch (AGB) models with a metallicity appropriate for stars in the Small Magellanic Cloud (SMC, Z= 0.0028, [Fe/H]~-0.7). New evolutionary sequences and post-processing nucleosynthesis results are presented for initial masses between 1 and 7 Msun, where the 7 Msun is a super-AGB star with an O-Ne core. Models above 1.15 Msun become carbon rich during the AGB, and hot bottom burning begins in models M > 3.75 Msun. We present stellar surface abundances as a function of thermal pulse number for elements between C to Bi and for a selection of isotopic ratios for elements up to Fe and Ni (e.g., 12C/13C), which can be compared to observations. The integrated stellar yields are presented for each model in the grid for hydrogen, helium and all stable elements from C to Bi. We present evolutionary sequences of intermediate-mass models between 4-7 Msun and nucleosynthesis results for three masses (M=3.75, 5, 7 Msun) including s-process elements for two widely used AGB mass-loss prescriptions. We discuss our new models in the context of evolved AGB stars and post-AGB stars in the Small Magellanic Clouds, barium stars in our Galaxy, the composition of Galactic globular clusters including Mg isotopes with a similar metallicity to our models, and to pre-solar grains which may have an origin in metal-poor AGB stars.

 
Aceptado para publicación en MNRAS | Enviado el 2018-03-07 | Proyecto P/308615