On-sky position (top-left). Black plus symbols mark the position of the M54 star cluster. Contour lines represent the distribution of Gaia DR3 Sgr candidate members selected on their proper motions as in our kinematical cut. Contour lines are mark the position at which the number of Sgr candidate members decreases by a factor of 2, 4, and 6, respectively. Top right panel: reduced proper motion space. Bottom-left: metallicity- radial velocity distribution. Bottom right: Kiel diagram of the PIGS/AAT data, including the Inner Galaxy and Sgr. Blue circles mark the final Sgr cut (356 stars), coral circles denote the Sgr stars from the kinematical selection (834 stars), brown crosses indicate the Sgr members selected from APOGEE DR17, and the grey dots correspond to the PIGS/AAT sample of the inner Galaxy. Sgr members from APOGEE DR17 were selected by imposing a similar RV and proper motion cut as that applied to our sample, along with a high signal-to-noise ratio in the spectra (> 70) to ensure the good quality of the RV and [Fe/H]. The APOGEE DR17 stars are not displayed in the Kiel diagram to better highlight the PIGS data.