[MKJ2009] 25 , the SIMBAD biblio

We present imaging observations of continuum emission from interstellar dust at 850 and 1200 µm of a section of the Galactic Plane covering 2 deg² centered at ℓ = 44°. Complementary jiggle-mapping and fast-scanning techniques were used, respectively, at these two wavelengths. The mapped area includes the well-known star formation regions W49 and G45.1/45.5. Using an automated clump-finding routine, we identify 132 compact 850 µm emission features within the region above a completeness level of about 200 mJy/beam. The positions of the latter objects were used to determine fluxes from the 1200 µm image. Spectral line data were subsequently obtained with the same observing beamwidth as at 850 µm for almost half of the objects; these were either imaged in the ¹³CO (3-2) line, or basic characteristics determined using the ¹²CO (3-2) transition. We use these data, supplemented by existing ¹³CO (1-0) and H I survey data, to determine distances and hence derive masses for the dust clump ensemble, assuming a uniform dust temperature of 15 K. From these data we find that the number-mass relationship for clumps in the field is similar to that found for individual star-forming regions.