Sgr dSph members RV and [Fe/H]

The targets were carefully selected (a) to sample the core of the main body of Sgr dSph while avoiding contamination from the central stellar nucleus, and (b) to prevent any bias on the metallicity distribution by selecting targets based on their Gaia parallax and proper motions.

All the targets selected in this way were confirmed as radial velocity members. We used this sample to derive the first metallicity distribution of the core of Sgr dSph which is virtually unaffected by metallicity biases. The observed distribution ranges from [Fe/H]~-2.3 to [Fe/H]~0.0, with a strong, symmetric, and relatively narrow peak around [Fe/H]~-0.5 and a weak and extended metal-poor tail, in which only 13.8+/-1.9% of the stars have [Fe/H]<-1.0.