T–T scatter plots between the NPIPE dust amplitude map at 545 GHz and three alternative thermal dust estimates. The panels show, from top to bottom, correlations with respect to: the HI4PI survey (Lenz et al. 2017); the Planck 2015 thermal dust amplitude map; and the GNILC 2018 thermal dust amplitude map. The top and middle panels show maps smoothed to a common resolution of 60′ FWHM, while the bottom panel employs a smoothing scale of 80′ FWHM, determined by the resolution of the GNILC map. The numbers marked by b₂, b₁, and b₀ (first plot) correspond to the best-fit polynomial parameters of a quadratic model (red dashed line, b₀ being the intercept), while a₁ and a₀ (all plots) correspond to the slope and intercept of the best fit line (green dashed line) through each distribution of points.