| Issue |
A&A
Volume 425, Number 2, October II 2004
|
|
|---|---|---|
| Page(s) | 697 - 705 | |
| Section | Stellar atmospheres | |
| DOI | https://doi.org/10.1051/0004-6361:20047191 | |
| Published online | 21 September 2004 | |
The [Zn/Fe] – [Fe/H] trend for disk and halo stars*
1
National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China e-mail: [cyq;zg]@bao.ac.cn
2
Institute of Physics and Astronomy, University of Aarhus, 8000 Aarhus C, Denmark e-mail: pen@phys.au.dk
Received:
4
February
2004
Accepted:
17
June
2004
Zn abundances, derived from a model atmosphere
analysis of the λ6362.35 Å
line, are presented for 44 thin disk, 10 thick disk and 8
halo dwarf stars in the metallicity range ![$-1.0 < \mbox{\rm [Fe/H]}< +0.2$](/articles/aa/abs/2004/38/aa0191-04/aa0191-04_tex_eq2.png)
.
It is found that [Zn/Fe] in thin disk
stars shows a slight increasing trend with decreasing metallicity
reaching a value ![$\mbox{\rm [Zn/Fe]}\simeq +0.1$](/articles/aa/abs/2004/38/aa0191-04/aa0191-04_tex_eq3.png)
at ![$\mbox{\rm [Fe/H]}= -0.6$](/articles/aa/abs/2004/38/aa0191-04/aa0191-04_tex_eq4.png)
.
The thick disk stars in the metallicity range ![$-0.9 < \mbox{\rm [Fe/H]}< -0.6$](/articles/aa/abs/2004/38/aa0191-04/aa0191-04_tex_eq5.png)
have an average ![$\mbox{\rm [Zn/Fe]}\simeq +0.15$](/articles/aa/abs/2004/38/aa0191-04/aa0191-04_tex_eq6.png)
dex, whereas five
alpha-poor and Ni-poor halo stars in the same metallicity range
have ![$\mbox{\rm [Zn/Fe]}\simeq 0.0$](/articles/aa/abs/2004/38/aa0191-04/aa0191-04_tex_eq7.png)
dex.
These results indicate that Zn is not an exact tracer of Fe as often
assumed in abundance studies of damped Lyman-alpha systems (DLAs).
A better understanding of the nucleosynthesis of Zn is needed
in order to obtain more detailed information on the past history
of star formation in DLAs from e.g. the observed sulphur/zinc ratio.
Key words: stars: abundances / stars: atmospheres / Galaxy: evolution / Galaxy: solar neighbourhood / galaxies: high-redshift
© ESO, 2004
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