Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-25T01:33:21.873Z Has data issue: false hasContentIssue false
  • English
  • Français

Peculiar Metal Poor Stars as Guides to Key Processes in the Early Halo

Published online by Cambridge University Press:  06 January 2014

Johannes Andersen  and
Birgitta Nordström
Johannes Andersen
Affiliation:
Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100, Copenhagen, Denmark email: [email protected], [email protected] Nordic Optical Telescope, Apartado 474, Santa Cruz de La Palma, Spain email: [email protected]
Birgitta Nordström
Affiliation:
Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100, Copenhagen, Denmark email: [email protected], [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Large photometric or spectroscopic surveys are used to sort stars into populations and define the main trends that characterise them, as diagnostics of their origin. Stars falling off the trends defined by the ‘normal’ stars are called ‘peculiar’ and typically eliminated in discussions of Galactic structure and evolution. In our programme on extremely metal-poor halo giants, we have recently focused on the small subgroup that is strongly enhanced in r-process elements, asking whether the chemical peculiarity is intrinsic to these stars or due to local surface pollution caused by mass transfer from a binary companion. Precise radial-velocity monitoring over several years turns out to disprove the binary hypothesis and has led to new insight in the processes of chemical enrichment in the early Galactic halo. An ongoing analogous programme on carbon-enhanced metal-poor giants is briefly described at the end.

Keywords

Galaxy: formationGalaxy: halostars: abundancesStars: carbonStars: chemically peculiarStars: abundancesBinaries: general
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 9 , Symposium S298: Setting the scene for Gaia and LAMOST , May 2013 , pp. 59 - 64
Copyright
Copyright © International Astronomical Union 2014 

References

Barklem, P. S., Christlieb, N., Beers, T. C., et al. 2005, A&A, 439, 129Google Scholar
Beers, T. C., Preston, G. W., & Schectman, S. A. 1985, AJ, 90, 2089Google Scholar
Beers, T. C., Preston, G. W., & Shectman, S. A. 1992, AJ, 103, 1987Google Scholar
Beers, T. C. & Christlieb, N. 2005, ARAA 43, 531Google Scholar
Bonifacio, P., Spite, M., Cayrel, R., et al. 2009, A&A, 501, 519Google Scholar
Cayrel, R., Depagne, E., Spite, M., et al. 2004, A&A 416, 1117Google Scholar
Cooke, R., Pettini, M., Steidel, C.C., et al. 2011, MNRAS 412, 1047Google Scholar
Frebel, A., Christlieb, N., Norris, J. E.et al. 2007, MNRAS, 380, L40Google Scholar
Hansen, T., Andersen, J., Nordström, B., Buchhave, L. A., & Beers, T. C. 2001 ApJL 743, L1Google Scholar
Hill, V., Plez, B., Cayrel, R., et al., 2002 A&A 387, 560Google Scholar
Jorissen, A., Van Eck, S., Mayor, M., & Udry, S. 1998 A&A 332, 877Google Scholar
McWilliam, A., Preston, G. W., Sneden, C., & Searle, L. 1995, AJ 109, 2757CrossRefGoogle Scholar
Siqueira Mello, C., Spite, M., Barbuy, B.et al. 2013, A&A, 550, 122Google Scholar
Norris, J. E., Yong, D., Bessell, M. S.et al. 2013, ApJ 762, 28Google Scholar
Ryan, S. G., Norris, J. E., & Beers, T. C. 1996, ApJ, 471, 254Google Scholar
Sneden, C., Preston, G. W., McWilliam, A., & Searle, L. 1994, ApJ, 431, L27Google Scholar
Qian, Y.-Z. & Wasserburg, G. 2001, ApJL, 552, L55Google Scholar