Two versions of the 'smooth' images are provided. Examples:

BLASTsep2006-12-21_250_smooth_2009-07-08.fits
BLASTsep2006-12-21_250_smooth_2010-07-09.fits

The 2009-07-08 versions were smoothed with a Gaussian the size 
of the BLAST beam. The 2010-07-09 versions were smoothed using 
a matched filter, as described in Chapin et al. (2010). The 
latter are the recommended 'smooth' images for this field.