The Pristine Inner Galaxy Survey (PIGS): X. Probing the early chemical evolution of the Sagittarius dwarf galaxy with carbon abundances

Abstract

We aim to constrain the chemo-dynamical properties of the Sagittarius (Sgr) dwarf galaxy using carbon abundances. At low metal- licities in particular, these properties reveal the early chemical evolution of a system, tracing the contributing supernovae (SNe) and how much of their ejecta eventually made it into the next stellar generation. Our sample from the Pristine Inner Galaxy Survey (PIGS) includes ~350 metal-poor ([Fe/H] +0.7) as that applied to the Galaxy at large ends up underpredicting the number of CEMP stars in DGs. Burthermore, for Sgr, a cut at [C/Fe] ∼ +0.35 may be more appropriate, which brings the frequency of CEMP stars in agreement with that of the whole Galaxy.