Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-25T16:59:30.405Z Has data issue: false hasContentIssue false
  • English
  • Français

Beryllium and the formation of the Thick Disk and of the Halo

Published online by Cambridge University Press:  01 June 2008

Luca Pasquini ,
R. Smiljanic ,
P. Bonifacio ,
R. Gratton ,
D. Galli  and
S. Randich
Luca Pasquini
Affiliation:
ESOGarching bei München, Germany email: [email protected]
R. Smiljanic
Affiliation:
ESOGarching bei München, Germany email: [email protected] Universidade de São Paolo, IAG, S. Paulo, Brazil
P. Bonifacio
Affiliation:
GEPI Observatoire de Paris - Meudon, France INAF, Osservatorio di Trieste, Trieste, Italy CIFIST Marie Curie Excellence Team
R. Gratton
Affiliation:
INAF-Osservatorio di Padova, Padova, Italy
D. Galli
Affiliation:
INAF-Osservatorio di Arcetri, Firenze, Italy
S. Randich
Affiliation:
INAF-Osservatorio di Arcetri, Firenze, Italy
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.

We use Beryllium to investigate star formation in the early Galaxy. Be has been demonstrated to be a good indicator of time in these early epochs. By analyzing the so-far largest sample of halo and thick disk metal poor stars, we find a clear scatter in Be for a given value of [Fe/H] and [O/H]. The scatter is very pronounced for Halo stars, while it is marginal for thick disk stars. Our halo stars separate in the [α/Fe] - Be diagram, showing two main branches: one indistinguishable from the thick disk stars, and one with lower [α/Fe] ratio. The stars belonging to this branch are characterized by highly eccentric orbits and small perigalactic radius (Rmin). Their kinematics are consistent with an accreted component.

Keywords

Stars: AbundancesGalaxy: HaloGalaxy: Disk
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 4 , Issue S254: The Galaxy Disk in Cosmological Context , June 2008 , pp. 203 - 208
Copyright
Copyright © International Astronomical Union 2009

References

Beers, T. C., Suzuki, T. K., & Yoshii, Y., 2000, in The Light Elements and their Evolution, ed. da Silva, L., de Medeiros, J. R. & Spite, M., IAU Symposium 198, 425.Google Scholar
Boesgaard, A. M., Deliyannis, C. P., King, J. R., Ryan, S. G., Vogt, S. S., & Beers, T. C., 1999, AJ, 117, 1549CrossRefGoogle Scholar
Dekker, H., D'Odorico, S., Kaufer, A., Delabre, B., & Kotzlowski, H., 2000, SPIE, 4008, 534Google Scholar
Duncan, D. K., Lambert, D. L., & Lemke, M., 1992, ApJ, 401, 584CrossRefGoogle Scholar
ESA, 1997, The Hipparcos and Tycho catalogues, ESA SP-1200Google Scholar
Gilmore, G., Gustafsson, B., Edvardsson, B., & Nissen, P. E., 1992, Nature, 357, 379CrossRefGoogle Scholar
Gratton, R. G., Carretta, E., Desidera, S., Lucatello, S., Mazzei, P., & Barbieri, M., 2003, A&A, 404, 187Google Scholar
Meneguzzi, M. & Reeves, H., 1975, A&A, 40, 99Google Scholar
Molaro, P., Bonifacio, P., Castelli, F., & Pasquini, L., 1997, A&A, 319, 593Google Scholar
Pasquini, L., Bonifacio, P., Randich, S., Galli, D., & Gratton, R. G., 2004, A&A, 426, 651Google Scholar
Pasquini, L., Bonifacio, P., Randich, S., Galli, D., Gratton, R. G., & Wolff, B., 2007, A&A, 464, 601Google Scholar
Pasquini, L., Galli, D., Gratton, R. G., Bonifacio, P., Randich, S., & Valle, G., 2005, A&A, 436, L57Google Scholar
Prantzos, N., Casse, M., & Vangioni-Flam, E., 1993, ApJ, 403, 630CrossRefGoogle Scholar
Rebolo, R., Abia, C., Beckman, J. E., & Molaro, P., 1988, A&A, 193, 193Google Scholar
Reeves, H., Fowler, W. A. & Hoyle, F., 1970, Nature, 226, 727CrossRefGoogle Scholar
Smiljanic, R., Pasquini, L., Primas, F., Mazzali, P. A., Galli, D., & Valle, G., 2008, MNRAS, 385, L93CrossRefGoogle Scholar
Suzuki, T. K. & Yoshii, Y., 2001, ApJ, 549, 303CrossRefGoogle Scholar
Suzuki, T. K., Yoshii, Y., & Kajino, T., 1999, ApJ, 522, L125CrossRefGoogle Scholar
Thomas, D., Schramm, D. N., Olive, K.A., & Fields, B. D., 1993, ApJ, 406, 569CrossRefGoogle Scholar
Valle, G., Ferrini, F., Galli, D., & Shore, S. N., 2002, ApJ, 566, 252CrossRefGoogle Scholar
Vangioni-Flam, E., Audouze, J., Oberto, Y., & Casse, M., 1990, ApJ, 364, 568CrossRefGoogle Scholar
Vangioni-Flam, E., Ramaty, R., Olive, K. A., & Cassé, M., 1998, A&A, 337, 714Google Scholar
Venn, K. A., Irwin, M., Shetrone, M. D., Tout, C. A., Hill, V., & Tolstoy, E., 2004, AJ, 128, 1177CrossRefGoogle Scholar