Fifty-one dense cores associated with water masers were mapped at 350 µm .
These cores are very luminous , 10 ^ { 3 } < \mbox { $L _ { bol } $ } / \mbox { L$ { } _ { \odot } $ } < 10 ^ { 6 } , indicative of the formation of massive stars .
Dust continuum contour maps , radial intensity profiles , and photometry are presented for these sources .
The submillimeter dust emission peak is , on average , nearly coincident with the water maser position .
The spectral energy distributions and normalized radial profiles of dust continuum emission were modeled for 31 sources using a one-dimensional dust radiative transfer code , assuming a power law density distribution in the envelope , n = n _ { f } ( r / r _ { f } ) ^ { - p } .
The best fit density power law exponent , p , ranged from 0.75 to 2.5 with \langle p \rangle = 1.8 \pm 0.4 , similar to the mean value found by Beuther et al .
( 2002 ) in a large sample of massive star forming regions .
The mean value of p is also comparable to that found in regions forming only low mass stars , but \langle n _ { f } \rangle is over two orders of magnitude greater for the massive cores .
The mean p is incompatible with a logatropic sphere ( p = 1 ) , but other star formation models can not be ruled out .
Different mass estimates are compared and mean masses of gas and dust are reported within a half-power radius determined from the dust emission , \langle { log } ( \mbox { $M ( < r _ { dec } ) $ } ) \rangle = 2.0 \pm 0.6 , and within a radius where the total density exceeds 10 ^ { 4 } cm ^ { -3 } , \mbox { $ \langle { log } ( \mbox { $M ( < r _ { n } ) $ } ) \rangle$ } = 2.5 \pm 0.6 .
Evolutionary indicators commonly used for low mass star formation , such as T _ { bol } and \mbox { $L _ { bol } $ } / \mbox { $L _ { smm } $ } , may have some utility for regions forming massive stars .
Additionally , for comparison with extragalactic star formation studies , the luminosity to dust mass ratio is calculated for these sources , \langle \mbox { $L _ { bol } $ } / M _ { D } \rangle = 1.4 \mbox { $ { } \times 10 ^ { 4 } $ } L _ { \odot } /M _ { \odot } , with a method most parallel to that used in studies of distant galaxies .
This ratio is similar to that seen in high redshift starburst galaxies .