**Table 1:** Observation parameters for the SCUBA jiggle-maps.
Map name	Night	Chop throw	Integrations $^{\rm a}$	Average $\tau$		rms noise (Jy/14 $^{\prime \prime }$ beam) $^{\rm b}$
				450 $\mu$ m	850 $\mu$ m	450 $\mu$ m	850 $\mu$ m
SFO 11	7th Jan. 2002	120 $^{\prime \prime }$	20	1.82	0.33	0.2	0.013
SFO 11NE	5th June 2002	180 $^{\prime \prime }$	6	1.94	0.34	0.1	0.020
SFO 11E	7th Jan. 2002	120 $^{\prime \prime }$	10	1.82	0.33	0.3	0.018

^a One SCUBA "integration'' is equivalent to 64 s of integration.
^b 450 $\mu$ m data smoothed to 14 $^{\prime \prime }$ resolution.