Correlations between EW₈₆₂ and E(B  −  V) derived from different extinction maps: (a) GSP-Phot, (b) Planck Collaboration Int. XLVIII (2016), (c) Schlegel et al. (1998), and (d) Green et al. (2019). The colours in each panel show the target number per 0.01 Å × 0.02 mag bin. The colour bar is the same as in Fig. 7. The red circles are the median values taken in EW₈₆₂ bins from 0 to 0.5 Å with a step of 0.05 Å. The red lines are linear fits to the red dots in each panel, respectively. The fitting gradients (α) and their uncertainties are indicated. They are also listed in Table 3. The orange and violet dashed lines in (b) and (c) are the fit results to GSP-Phot and Green et al. (2019), respectively.