SCUBA observations of NGC 6946 [Letter]

We present sub-millimetre images of the spiral galaxy NGC 6946 at 450 and 850 mu m. The observations have been carried out using the scan/map imaging mode of the Sub-millimetre Common User Bolometer Array (SCUBA) at the James Clark Maxwell Telescope (JCMT). The comparison with a (12)CO(2-1) line emission map from IRAM and with an U-band image, clearly shows that the 850 mu m emission is associated with molecular gas and bright star-forming regions, tracing the spiral arms. We place an upper limit of 0.7 for the V-band optical depth of dust associated with a diffuse atomic component. Based on observations at the James Clerk Maxwell Telescope. JCMT is operated by The Joint Astronomy Centre on behalf of the Particle Physics and Astronomy Research Council of the United Kingdom, the Netherlands Organisation for Scientific Research, and the National Research Council of Canada