Far-infrared observations of G351.6-1.3/G351.7-1.2 region

An area of about 20 arcmin × 25 arcmin around the H II region-molecular cloud complexes G351.6-1.3 and G351.7-1.2 has been mapped in a 120-300 micron far-infrared band with a spatial resolution of about 1.5 arcmin. Besides the two main sources, five weaker sources have been seen. The IRAS two-dimensional COADD data of the same region at 60 microns and 100 microns have been deconvolved for comparison with the 150 micron intensity map. Combining all the available far-infrared measurements, dust temperature, optical depth, far-infrared luminosity, etc, have been derived for the individual sources in this complex. Spectra have been constructed for the two main sources using all available data. These have been compared with the results of radiation transfer calculations for a spherically symmetric model. Information has been derived on the nature of the dust and its distribution in the main source in G351.6-1.3. A mixture of graphite and silicate grains gives a good fit to the observed spectrum. The favored radial dust density distribution is uniform