Observations (left column), models (middle column), and residuals (right column) of the HeViCS field in the SPIRE 250 μm band. Observations and models were subtracted by the large-scale terms O_ν + E_ν × (b−b₀) and are shown on the same color scale. The color scale of the residuals goes from −4 to 4σ_R (Table 1); round white areas show the object mask applied before the fitting, while white contours encircle the regions where residuals are larger than 3σ_R (excluded during the fitting). The orange numbered ellipses and square regions refer to the high positive residual regions listed in Table 3 and shown in Fig. 9. The magenta circle labeled “N” highlights a region with high negative residuals; the magenta circle labeled “G” is centered on an unmasked Virgo cluster galaxy.