HIGH-RESOLUTION MILLIMETER AND SUBMILLIMETER CONTINUUM OBSERVATIONS OF M17SW .2. IDENTIFICATION OF EMBEDDED SOURCES ASSOCIATED WITH H2O MASERS

The M17SW molecular cloud core has been mapped in continuum emission at 450, 600, 800, 1100 and 1300 mum, using the James Clerk Maxwell Telescope, with an angular resolution of 8 arcsec for the shortest wavelength. The 450- and 600-mum maps, in particular, show the dust emission to be highly clumped; these clumps are, in some cases, identified with those seen in previous optically thin line observations. The continuum observations are consistent with a single greybody at a temperature of 30 K, and suggest masses of 7600 and 1300 M. for the entire M17SW region and the northern condensation respectively; the corresponding total integrated luminosities for each region are 2.4 x 10(5) and 4.2 x 10(4) L.. Using an analytical inversion technique, however, which allows for a continuous range of dust temperatures, we find a mass-weighted average temperature of almost-equal-to 18 K, and masses for M17SW and the northern condensation alone of 1.6 x 10(4) and 2000 M. respectively. The flux from the northern condensation is dominated by three main components, each of which lies within a few arcsec of an H2O maser. All these objects have central densities greater than the Jeans critical density, and have masses in the range 300 to 450 M., with luminosities of 8000 to 12 000 L.; these values are consistent with them containing very deeply embedded young stellar objects of mass is similar to 10 M..