Metal-poor stars are likely to be product of the earliest generation of stars formed in the Universe. As the atmosphere of the stars preserves information about the interstellar medium (ISM) where they were formed, observational analyzes of the atmosphere of the metal-poor stars in our Galaxy provide us with archaeological information about the evolution of the early Galaxy. Moreover, a detailed study of the chemistry on the surface of these objects, in particular, provides information about the formation and evolution of the elements and contributes to improving theoretical models for the involved nucleosynthesis processes. In the present work, we are using high-resolution (R ~ 50000) spectroscopy to analyze a large sample (>100) of stars in the metallicity range -3.0 < [Fe/H] < -0.7. In order to avoid the opacity due to the presence of molecular bands of carbon, the selected sample is not C-enhanced. Our aim is to investigate the chemical pattern for those elements produced by neutron-capture and heavier than rubidium (Z ≥ 37). This includes Ba and Eu, key elements to trace the s- and r-process, respectively. In this talk, we will present the results which include the abundances for Ba, Eu as well the light elements of the neutron-capture process for the whole sample of low-metallicity C-normal stars.
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