The r s CEMP stars and AGB supernovae

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The rs CEMP stars and AGB supernovae

• Maria Lugaro
• University of Utrecht (NL)

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rs CEMP stars
-3.1 lt Fe/H lt -2.1
Eu/Fe gt 1
1.7 lt C/Fe lt 2.6
Ba/Fe gt 1
Similarity in the chemical composition an
homogenous sample. (see, e.g., Jonsell et al.
2006 AA)
17 rs CEMP stars and 9 formation scenarios

1. Radiative levitation
2. A r-rich ISM and self-pollution
3. Binary system out of r-rich ISM and AGB pollution
4. Triple system with SN- and AGB-pollution
5. Binary system with AGB- and 1.5 or e-capture
   SN-pollution
6. Binary system with AGB- and AIC-pollution
7. Binary system with only AGB-pollution
8. A relation to blue stragglers?
9. Origin from a common cloud of rs stars

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Zijlstra (2004) MNRAS the initial-final mass
relation steepens at low Z, due to low mass-loss
efficiency
Yields from AGB stars (Karakas Lattanzio
2007) At Fe/H-2.3
2.8
CgtN
CltN
Hot bottom burning
rs CEMP stars CgtN
Wanajo et al. (2006), ApJ the case of an 8-10 M?
companion
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Conclusion
Lets not forget hot bottom burning in relation
to rs CEMP stars