Dust filaments and star formation in OMC-2 and OMC-3

We have mapped the 1300 mu m dust emission of a 6' X 16' field in the OMC-2 and -3 region and detected an extended filamentary structure with at least 11 embedded condensations in OMC-2 and 10 in OMC-3. Six have been observed previously at 1300 mu m, and two were also detected by IRAS. We observed eight of the new sources at six wave bands from 350 to 2000 mu m and derived upper limits for their far-infrared (FIR) emission from the IRAS raw data. The millimeter/submillimeter emission originates from cold dust (T-d similar to 20 K), and the individual components have gas masses of 5 M. < M(gas) < 36 M.. The ratio L(bol)/L(smm) is below 70 for six sources associated with OMC-3, indicating that they are class 0-type objects. Condensations in the OMC-2 region have L(bol)/L(smm) less than or equal to 360, suggesting an evolutionary effect from north to south. We report the discovery of a highly collimated bipolar CO outflow, most likely driven by the source OMC-3 MMS 8. The flow is over 5' (0.7 pc) long and less than 1' (0.15 pc) wide and is oriented nearly east-west. Less prominent outflows are associated with OMC-2 FIR 2/3 and OMC-3 MMS 6. The 1300 mu m continuum emission is confined to a ridge less than 1' wide while the emission in J = 2-1 (CO)-C-13, (CO)-O-18, and CS is between 5' and 10' wide. The continuum emission is displaced toward the eastern side of the molecular ridge that contains it. Most 1300 mu m sources lie in or close to line emission peaks. However, not all line emission peaks contain prominent 1300 mu m continuum sources. The curved filamentary structure of the large-scale dust and molecular emission is likely the result of compression by the superbubble centered similar to 25-70 pc further north, plus the impact of energy from the younger Ic subgroup of the Orion OB association, which lies 10-50 pc in front of our mapped region, and by the very recent expansion of the NGC 1977 and M42H II regions.