(J − K_S, J) CMD for four selected GIBS fields. The gray-scale image shows the number density of the stars selected from VVV–DR2 catalog. The red dots are the GIBS targets in each field. JK_S photometry of GIBS targets are provided by the PSF photometry catalog developed by Surot et al. (2019). The dashed green lines indicate the 1σ extent widths around the RC peak densities for the regions defined by the range of J magnitudes of GIBS targets in each field (dashed orange lines). The name and coordinates of each field are indicated at the upper left corner in each panel.