| |
 |
| Paper: |
The Chemical Imprint of Super-AGB Stars |
| Volume: |
378, Why Galaxies Care About AGB Stars: Their Importance as Actors and Probes |
| Page: |
9 |
| Authors: |
Siess, L. |
| Abstract: |
The evolution and nucleosynthesis of stars in the mass range ~ 7 − 11M⊙ is reviewed. The main evolutionary features can be summarized as follows: off-center carbon ignition followed by the propagation of a flame to the center, formation of a neon-oxygen core and subsequent development of recurrent instabilities in the helium burning shell during the so-called thermally pulsing super-AGB (SAGB) phase. Our analysis of the pulse properties and nucleosynthesis show that owing to large dilution factors, the surface modifications induced by third dredge-up episodes are weak. The chemical imprint of SAGB stars mainly results from the action of hot-bottom burning, namely a large production of 13C, 14N, 25Mg, 26Al and potentially of 23Na. We also briefly describe how the mass range where SAGB stars lie depends on the metallicity. |
|
|
|
|
|
