| Full text | |
| Author(s): Show less - |
Yong, David
[1]
;
Melendez, Jorge
[2]
;
Grundahl, Frank
[3]
;
Roederer, Ian U.
[4]
;
Norris, John E.
[1]
;
Milone, A. P.
[1]
;
Marino, A. F.
[1]
;
Coelho, P.
[5]
;
McArthur, Barbara E.
[6]
;
Lind, K.
[7]
;
Collet, R.
[1]
;
Asplund, Martin
[1]
Total Authors: 12
|
| Affiliation: | [1] Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611 - Australia
[2] Univ Sao Paulo, Dept Astron IAG, BR-05508900 Sao Paulo - Brazil
[3] Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, DK-8000 Aarhus C - Denmark
[4] Carnegie Observ, Pasadena, CA 91101 - USA
[5] Univ Cruzeiro Sul, Nucleo Astrofis Teor, BR-01506000 Sao Paulo - Brazil
[6] Univ Texas Austin, McDonald Observ, Austin, TX 78712 - USA
[7] Univ Cambridge, Cambridge CB3 0HA - England
Total Affiliations: 7
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 434, n. 4, p. 3542-3565, OCT 2013. |
| Web of Science Citations: | 44 |
| Abstract | |
We report on a strictly differential line-by-line analysis of high-quality UVES spectra of bright giants in the metal-poor globular cluster NGC 6752. We achieved high precision differential chemical abundance measurements for Fe, Na, Si, Ca, Ti, Cr, Ni, Zn, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy with uncertainties as low as similar to 0.01 dex (similar to 2 per cent). We obtained the following main results. (1) The observed abundance dispersions are a factor of similar to 2 larger than the average measurement uncertainty. (2) There are positive correlations, of high statistical significance, between all elements and Na. (3) For any pair of elements, there are positive correlations of high statistical significance, although the amplitudes of the abundance variations are small. Removing abundance trends with effective temperature and/or using a different pair of reference stars does not alter these results. These abundance variations and correlations may reflect a combination of (a) He abundance variations and (b) inhomogeneous chemical evolution in the pre- or protocluster environment. Regarding the former, the current constraints on delta Y from photometry likely preclude He as being the sole explanation. Regarding the latter, the nucleosynthetic source(s) must have synthesized Na, alpha, Fe-peak and neutron-capture elements and in constant amounts for species heavier than Si; no individual object can achieve such nucleosynthesis. We speculate that other, if not all, globular clusters may exhibit comparable abundance variations and correlations to NGC 6752 if subjected to a similarly precise analysis. (AU) | |
| FAPESP's process: | 08/58406-4 - The modeling of stellar populations and detailed abundance patterns |
| Grantee: | Paula Rodrigues Teixeira Coelho |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 12/24392-2 - High precision spectroscopy: impact in the study of planets, stars, the galaxy and cosmology |
| Grantee: | Jorge Luis Melendez Moreno |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 10/17510-3 - Influence of planet formation in the chemical composition of solar type stars |
| Grantee: | Jorge Luis Melendez Moreno |
| Support Opportunities: | Regular Research Grants |