TY  - JOUR
A1  - Palmerini, Sara
A1  - Cristallo, Sergio
A1  - Piersanti, Luciano
A1  - Vescovi, Diego
A1  - Busso, Maurizio
T1  - Group II oxide grains: how massive are their AGB star progenitors?
T2  - Universe
N2  - Presolar grains and their isotopic compositions provide valuable constraints to AGB star nucleosynthesis. However, there is a sample of O- and Al-rich dust, known as group 2 oxide grains, whose origin is difficult to address. On the one hand, the 17O/16O isotopic ratios shown by those grains are similar to the ones observed in low-mass red giant stars. On the other hand, their large 18O depletion and 26Al enrichment are challenging to account for. Two different classes of AGB stars have been proposed as progenitors of this kind of stellar dust: intermediate mass AGBs with hot bottom burning, or low mass AGBs where deep mixing is at play. Our models of low-mass AGB stars with a bottom-up deep mixing are shown to be likely progenitors of group 2 grains, reproducing together the 17O/16O, 18O/16O and 26Al/27Al values found in those grains and being less sensitive to nuclear physics inputs than our intermediate-mass models with hot bottom burning.
KW  - AGB star
KW  - presolar grain
KW  - Nucleosynthesis-Star
KW  - abundances
KW  - reaction rate
KW  - isotopic abundance
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62173
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-621736
SN  - 2218-1997
N1  - D.V. acknowledges the financial support of the German-Israeli Foundation (GIF No. I-1500- 303.7/2019).
VL  - 7
IS  - 6, art. 175
SP  - 1
EP  - 15
PB  - MDPI
CY  - Basel
ER  -