- (1) Carnegie Observatories, grid.432988.c
- (2) Heidelberg University, grid.7700.0
- (3) Aarhus University, grid.7048.b, AU
- (4) University of Copenhagen, grid.5254.6, KU
- (5) University of Notre Dame, grid.131063.6
- (6) Harvard-Smithsonian Center for Astrophysics, grid.455754.2
Context. Detailed spectroscopic studies of metal-poor halo stars have highlighted the important role of carbon-enhanced metal-poor (CEMP) stars in understanding the early production and ejection of carbon in the Galaxy and in identifying the progenitors of the CEMP stars among the first stars formed after the Big Bang. Recent work has also classified the CEMP stars by absolute carbon abundance, A(C), into high- and low-C bands, mostly populated by binary and single stars, respectively.