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The Mystery of CEMPs+r Stars and the Dual Core-Flash Neutron Superburst

Published online by Cambridge University Press:  05 March 2013

M. Lugaro ,
S. W. Campbell  and
S. E. de Mink
M. Lugaro*
Affiliation:
Centre for Stellar and Planetary Astrophysics, School of Mathematical Sciences, Monash University, Clayton, VIC 3800 Sterrekundig Instituut, University of Utrecht, Postbus 80 000, 3508 TA Utrecht, The Netherlands
S. W. Campbell
Affiliation:
Centre for Stellar and Planetary Astrophysics, School of Mathematical Sciences, Monash University, Clayton, VIC 3800 Departament de Física i Enginyeria Nuclear, EUETIB, Universita Politècnica de Catalunya, E-08036, Barcelona, Spain
S. E. de Mink
Affiliation:
Sterrekundig Instituut, University of Utrecht, Postbus 80 000, 3508 TA Utrecht, The Netherlands
*
DCorresponding author. Email: Maria.Lugaro@sci.monash.edu.au
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Abstract

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Carbon-enhanced metal-poor (CEMPs+r) stars show large enhancements of elements produced both by the slow and the rapid neutron capture processes (the s and r process, respectively) and represent a relatively large fraction, 30% to 50%, of the CEMP population. Many scenarios have been proposed to explain this peculiar chemical composition and most of them involve a binary companion producing the s-process elements during its Asymptotic Giant Branch (AGB) phase. The problem is that none of the proposed explanations appears to be able to account for all observational constraints, hence, alternatives are needed to be put forward and investigated. In this spirit, we propose a new scenario for the formation of CEMPs+r stars based on S. W. Campbell's finding that during the ‘dual core flash’ in low-mass stars of extremely low metallicity, when protons are ingested in the He-flash convective zone, a ‘neutron superburst’ is produced. Further calculations are needed to verify if this neutron superburst could make the r-process component observed in CEMPs+r, as well as their Fe abundances. The s-process component would then be produced during the following AGB phase.

Keywords

nuclear reactions, nucleosynthesis, abundancesstars: AGB and post-AGBbinaries: generalstars: chemically peculiarstars: Population II
Type
CEMP Stars
Information
Publications of the Astronomical Society of Australia , Volume 26 , Issue 3 , 2009 , pp. 322 - 326
Copyright
Copyright © Astronomical Society of Australia 2009

References

Aoki, W., Honda, S., Beers, T. C. & Sneden, C. 2003a, ApJ, 586, 506 Google Scholar
Aoki, W. et al., 2003b, ApJ, 592, L67 Google Scholar
Bisterzo, S. 2007, PhD Thesis, Universitá di Torino Google Scholar
Campbell, S. W. 2007, PhD Thesis, Monash University Google Scholar
Campbell, S. W. & Lattanzio, J. C. 2008, A&A, 490, 769 Google Scholar
Cohen, J. G., Christlieb, N., Qian, Y.-Z. &Amp; Wasserburg, G. J. 2003, ApJ, 588, 1082 Google Scholar
Fujimoto, M. Y., Iben, I. J. & Hollowell, D. 1990, ApJ, 349, 580 Google Scholar
Fujimoto, M. Y., Ikeda, Y. & Iben, I. J. 2000, ApJ, 529, L25 Google Scholar
Gallino, R., Arlandini, C., Busso, M., Lugaro, M., Travaglio, C., Straniero, O., Chieffi, A. & Limongi, M. 1998, ApJ, 497, 388 Google Scholar
Hollowell, D., Iben, I. J. & Fujimoto, M. Y., 1990, ApJ, 351, 245 Google Scholar
Ivans, I. I., Sneden, C., Gallino, R., Cowan, J. J. & Preston, G. W., 2005, ApJ, 627, L145 Google Scholar
Jonsell, K., Barklem, P. S., Gustafsson, B., Christlieb, N., Hill, V., Beers, T. C. & Holmberg, J. 2006, A&A, 451, 651 Google Scholar
Karakas, A. & Lattanzio, J. C. 2007, PASA, 24, 103 Google Scholar
Lucatello, S., Tsangarides, S., Beers, T. C., Carretta, E., Gratton, R. G. & Ryan, S. G. 2005, ApJ, 625, 825 Google Scholar
Lugaro, M. et al., 2008, A&A, 484, L27 Google Scholar
Mac Low, M. M. 2008, ASPC, 387, 148 Google Scholar
Megeath, S. T., Gaidos, E., Hester, J. J.,Adams, F. C., Bally, J., Lee, J.-E. & Wolk, S. 2008, ASPC, 384, 393 Google Scholar
Picardi, I., Chieffi, A., Limongi, M., Pisanti, O., Miele, G., Mangano, G. & Imbriani, G. 2004, ApJ, 609, 1035 Google Scholar
Qian, Y.-Z. & Wasserburg, G. J. 2003, ApJ, 588, 1099 Google Scholar
Schuler, S. C., Cunha, K., Smith, V. V., Sivarani, T., Beers, T. C. & Lee, Y. S., 2007, ApJ, 667, L81 Google Scholar
Sneden, C., Cowan, J. J., Lawler, J. E., Burles, S., Beers, T. C. & Fuller, G. M. 2002, ApJ, 566, L25 Google Scholar
Sneden, C., Preston, G. W., McWilliam, A. & Searle, L. 1994, ApJ, 431, L27 Google Scholar
Stancliffe, R. J., Izzard, R. G. & Tout, C. A., 2005, MNRAS, 356, L1 Google Scholar
Suda, T. et al., 2008, PASJ, 60, 1159 Google Scholar
Thompson, I. B. et al., 2008, ApJ, 677, 556 Google Scholar
Travaglio, C., Galli, D., Gallino, R., Busso, M., Ferrini, F. & Straniero, O. 1999, ApJ, 521, 691 Google Scholar
Vanhala, H. A. T. & Cameron, A. G. W. 1998, ApJ, 508, 291 Google Scholar
Wanajo, S., Nomoto, K., Iwamoto, N., Ishimaru, Y. & Beers, T. C., 2006, ApJ, 636, 842 Google Scholar
Zijlstra, A. A. 2004, MNRAS, 348, L23 Google Scholar