Separation of BHB stars from high log g contaminants in the T_eff–log g space. The top panel shows the density distribution of the high-latitude photometric-cut BHB candidates in T_eff − log g space. The bottom panel shows a small fraction of our candidates that have been previously identified as BHB (blue points) or high surface gravity stars (orange points) in the SEGUE data by Barbosa et al. (2022). Two black lines are employed to separate these two types of stars, and we apply this cut to the whole candidates as shown in the top panel.