[C/O] Observations in Low-[Fe/H] Halo Stars

Fabbian, D.; Nissen, P. E.; Asplund, M.; Akerman, C. J.; Pettini, M.
Bibliographical reference

Precision Spectroscopy in Astrophysics, Proceedings of the ESO/Lisbon/Aveiro Conference held in Aveiro, Portugal, 11-15 September 2006. Edited by N.C. Santos, L. Pasquini, A.C.M. Correia, and M. Romanielleo. Garching, Germany, 2008 pp. 45-46

Advertised on:
0
2008
Number of authors
5
IAC number of authors
0
Citations
1
Refereed citations
0
Description
We have observed 15 halo stars to determine the [C/O] behaviour at low [Fe/H]. Making use of our recent non-LTE calculations, which show that the high excitation C and O lines used in previous studies in the literature are affected by very significant departures from LTE, we aim to obtain accurate [C/O] ratios down to [Fe/H]˜ —3.2, which will enable us to shed light on the possible presence of an upturn of [C/O] at low metallicities.