F480M versus F162M-F480M CMD. The purple box highlights the RC feature, and the black arrow is the reddening vector for AF480M = 0.3 mag. The two purple arrows indicate the bright (top) and faint (bottom) RC features. The inset shows a zoomed-in view of the RC region, where the two features are identified using the GMM approach described in Sect. 4.1. The cyan points correspond to the positions of the RC features in each bin, and the cyan lines show the best-fitting linear regressions. The uncertainties, although included, are smaller than the marker size and therefore not visible. The purple box in the CMD is also included for reference.

We also observe the presence of a bright and a faint RC. This double RC feature has been interpreted as evidence of two stellar populations formed in separate star formation episodes - an older component (∼8Gyr) and a younger one (∼1Gyr; see Nogueras-Lara et al. 2019a). Additionally, we considered stars with F162M-F480M ≲3 mag to belong to the foreground population (e.g. Nogueras-Lara et al. 2021a).