Observations of five moderate-luminosity far-infrared sources in Orion and Monoceros

Far-infrared and submillimeter observations of Orion Molecular Cloud-2 (OMC-2), OMC-1, OMC-3, NGC 2024 and Monoceros R2 are reported. The areas surveyed include far-infrared sources with luminosities between 100 and 250,000 solar luminosities. The data are employed to estimate masses and column densities for the radiating clouds, the radial dependence of the density in the clouds, and the masses of the stellar clusters. Brightness temperatures of both the extended and compact far-infrared sources in OMC-2 are found to be lower than the brightness temperature of the extended (C-12)O emission, indicating an important role in (C-12)O heating for stars external to the compact center.