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Lithium production by thermohaline mixing in low-mass, low-metallicity asymptotic giant branch stars

Published online by Cambridge University Press:  23 April 2010

Richard J. Stancliffe ,
George C. Angelou  and
John C. Lattanzio
Richard J. Stancliffe
Affiliation:
Centre for Stellar and Planetary Astrophysics, Monash University, VIC 3800, Australia email: Richard.Stancliffe@sci.monash.edu.au
George C. Angelou
Affiliation:
Centre for Stellar and Planetary Astrophysics, Monash University, VIC 3800, Australia email: Richard.Stancliffe@sci.monash.edu.au
John C. Lattanzio
Affiliation:
Centre for Stellar and Planetary Astrophysics, Monash University, VIC 3800, Australia email: Richard.Stancliffe@sci.monash.edu.au
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Abstract

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We examine the effects of thermohaline mixing on the composition of the envelopes of low-metallicity asymptotic giant branch (AGB) stars. We have evolved models of 1, 1.5 and 2M⊙ and of metallicity Z = 10−4 from the pre-main sequence to the end of the thermal pulsing asymptotic giant branch with thermohaline mixing applied throughout the simulations. We find that the small amount of 3He that remains after the first giant branch is enough to drive thermohaline mixing on the AGB and that the mixing is most efficient in the early thermal pulses, with the efficiency dropping from pulse to pulse. We note a surprising increase in the 7Li abundance, with log10ϵ(7Li) reaching values of over 2.5 in the 1.5M⊙ model. It is thus possible to get stars which are both C- and Li-rich at the same time. We compare our models to measurements of carbon and lithium in carbon-enhanced metal-poor stars which have not yet reached the giant branch. These models can simultaneously reproduced the observed C and Li abundances of carbon-enhanced metal-poor turn-off stars that are Li-rich.

Keywords

Stars: evolutionAGB and post-AGBPopulation IIcarbon
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 5 , Symposium S268: Light Elements in the Universe , November 2009 , pp. 405 - 410
Copyright
Copyright © International Astronomical Union 2010

References

Abia, C. & Isern, J. 1997, MNRAS, 289, L11CrossRefGoogle Scholar
Anders, E. & Grevesse, N. 1989, Geo.Cosmo.Acta, 53, 197CrossRefGoogle Scholar
Aoki, W., Beers, T. C., Sivarani, T., Marsteller, B., Lee, Y. S., Honda, S., Norris, J. E., Ryan, S. G., & Carollo, D. 2008, ApJ, 678, 1351CrossRefGoogle Scholar
Beers, T. C. & Christlieb, N. 2005, ARA&A, 43, 531Google Scholar
Cameron, A. G. W. & Fowler, W. A. 1971, ApJ, 164, 111CrossRefGoogle Scholar
Campbell, S. W. & Lattanzio, J. C. 2008, A&A, 490, 769Google Scholar
Charbonnel, C. & Zahn, J.-P. 2007, A&A, 467, L15Google Scholar
Eggleton, P. P., Dearborn, D. S. P., & Lattanzio, J. C. 2006, Science, 314, 1580CrossRefGoogle Scholar
Eggleton, P. P., Dearborn, D. S. P., & Lattanzio, J. C. 2008, ApJ, 677, 581CrossRefGoogle Scholar
Fujimoto, M. Y., Iben, I. J., & Hollowell, D. 1990, ApJ, 349, 580CrossRefGoogle Scholar
Kippenhahn, R., Ruschenplatt, G., & Thomas, H.-C. 1980, A&A, 91, 175Google Scholar
Lau, H. H. B., Stancliffe, R. J. & Tout, C. A. 2009, MNRAS, 396, 1046CrossRefGoogle Scholar
Lebzelter, T., Lederer, M. T., Cristallo, S., Hinkle, K. H., Straniero, O., & Aringer, B. 2008, A&A, 486, 511Google Scholar
Lucatello, S., Gratton, R., Cohen, J. G., Beers, T. C., Christlieb, N., Carretta, E., & Ramírez, S. 2003, AJ, 125, 875CrossRefGoogle Scholar
Lugaro, M., Campbell, S. W., & de Mink, S. E. 2009, PASA, 26, 322CrossRefGoogle Scholar
Nollett, K. M., Busso, M., & Wasserburg, G. J. 2003, ApJ, 582, 1036CrossRefGoogle Scholar
Reimers, D. 1975, Memoires of the Societe Royale des Sciences de Liege, 8, 369Google Scholar
Richard, O., Michaud, G., & Richer, J. 2005, ApJ, 619, 538CrossRefGoogle Scholar
Sivarani, T., Beers, T. C., Bonifacio, P., Molaro, P., Cayrel, R., Herwig, F., Spite, M., Spite, F., Plez, B., Andersen, J., Barbuy, B., Depagne, E., Hill, V., François, P., Nordström, B., & Primas, F. 2006, A&A, 459, 125Google Scholar
Stancliffe, R. J. 2009, MNRAS, 394, 1051CrossRefGoogle Scholar
Stancliffe, R. J., Church, R. P., Angelou, G. C., & Lattanzio, J. C. 2009, MNRAS, 396, 2313CrossRefGoogle Scholar
Stancliffe, R. J. & Eldridge, J. J. 2009, MNRAS, 396, 1699CrossRefGoogle Scholar
Stancliffe, R. J. & Glebbeek, E. 2008, MNRAS, 389, 1828CrossRefGoogle Scholar
Stancliffe, R. J., Glebbeek, E., Izzard, R. G., & Pols, O. R. 2007, A&A, 464, L57Google Scholar
Suda, T., Katsuta, Y., Yamada, S., Suwa, T., Ishizuka, C., Komiya, Y., Sorai, K., Aikawa, M., & Fujimoto, M. Y. 2008, PASJ, 60, 1159CrossRefGoogle Scholar
Thompson, I. B., Ivans, I. I., Bisterzo, S., Sneden, C., Gallino, R., Vauclair, S., Burley, G. S., Shectman, S. A., & Preston, G. W. 2008, ApJ, 677, 556CrossRefGoogle Scholar
Uttenthaler, S., Lebzelter, T., Palmerini, S., Busso, M., Aringer, B., & Lederer, M. T. 2007, A&A, 471, L41Google Scholar
Vassiliadis, E. & Wood, P. R. 1993, ApJ, 413, 641CrossRefGoogle Scholar