| Full text | |
| Author(s): Show less - |
Smiljanic, Rodolfo
;
Pasquini, L.
;
Bonifacio, P.
;
Galli, D.
;
Barbuy, B.
;
Gratton, R.
;
Randich, S.
;
Charbonnel, C
;
Tosi, M
;
Primas, F
;
Chiappini, C
Total Authors: 11
|
| Document type: | Journal article |
| Source: | COSMIC MAGNETIC FIELDS: FROM PLANETS, TO STARS AND GALAXIES; v. N/A, n. 268, p. 2-pg., 2010-01-01. |
| Abstract | |
The single stable isotope of beryllium is it pure product of cosmic-ray spallation in the ISM Assuming that the cosmic-rays are globally transported across the Galaxy, the beryllium production should be a widespread process and its abundance should be roughly homogeneous in the early-Galaxy at a given time. Thus, it could be useful as a tracer of time. In an investigation of the use of Be as a cosmochronometer and of its evolution in the Galaxy, we found evidence that, in a log(Be/H) vs (a/Fe] diagram the halo stars separate into two components. One is consistent with predictions of evolutionary models while the other is chemically indistinguishable from the thick-disk stars. This is interpreted as a difference in the star formation history of the two components and suggests that the local halo is not a single uniform population where a clear age-metallicity relation can be defined. We also found evidence that the star formation rate was lower in the outer regions of the thick disk, pointing towards an inside-out formation (AU) | |
| FAPESP's process: | 04/13667-4 - Molecular bands and spectral indices in the ultraviolet region 3200-4500a |
| Grantee: | Rodolfo Henrique Silva Smiljanic |
| Support Opportunities: | Scholarships in Brazil - Doctorate |