Submillimeter observations of dense clumps in the infrared dark cloud G049.40-00.01

We obtained 350 and 850 μm continuum maps of the infrared dark cloud G049.40-00.01. Twenty-one dense clumps were identified within G049.40-00.01 based on the 350 μm continuum map with an angular resolution of about 96. We present submillimeter continuum maps and report physical properties of the clumps. The masses of clumps range from 50 to 600 M. About 70% of the clumps are associated with bright 24 μm emission sources, and they may contain protostars. The two most massive clumps show extended, enhanced 4.5 μm emission indicating vigorous star-forming activity. The clump-size-mass distribution suggests that many of them are forming high-mass stars. G049.40-00.01 contains numerous objects in various evolutionary stages of star formation, from pre-protostellar clumps to H II regions.