Program: GS-2021A-Q-228

Carbon-enhanced metal-poor (CEMP) stars are among the most important objects for constraining the formation and evolution of the first stellar populations in the Galaxy. Proposed formation channels for CEMP stars include mass transfer in a binary system and faint SNe with mixing and fallback. Fluorine production at low metallicity is extremely sensitive to the physical conditions where produced. Thus, Fluorine measurements in CEMP stars provide a direct test of CEMP formation scenarios, nucleosynthesis and chemical enrichment mechanisms in the early beginnings of our Galaxy. At low-metallicity, [Fe/H] < -2, just one reliable Fluorine measurement and a handful of upper limits have been reported. We propose to obtain GEMINI-S/IGRINS spectra for 5 CEMP stars ([Fe/H] < -2) in order to test state-of-the-art theoretical models for faint SNe (Tominaga et al. 2014) and AGB mass transfer (Abate et al. 2015). Our targets were carefully selected to have detectable F abundances and will increase considerably the current F measurements sample on very-metal poor stars. The expected outcome of our observations is to validate (or constrain) CEMP formation channels and nucleosynthesis in the early Galaxy.