Extended emission maps of the full Herschel fields. The name of the field is written below frames a and b. The two fields are divided by the horizontal line. (a) 250–500 μm temperature with constant β = 1.8. (b) 250–500 μm column density N(H₂) with constant β = 1.8. (c) 160–500 μm temperature with background subtraction and varied spectral index. (d) 160–500 μm spectral index with background subtraction.