2003A&A...408..245N

We have revisited the stellar content of OMC2 and OMC3 by means of MIR imaging and NIR photometry; in addition, we have extended the existing (sub)mm maps by a huge 1200µm map obtained with SIMBA showing new sources and filamentary features for the first time at that wavelength. The MIR data reveal 43 new sources at N and Q which are partly associated with dense condensations at millimetre wavelengths. Six close binary sources could be resolved at locations where existing (sub)mm maps only show single emission peaks; three of them are classified as early (B-type) systems, one of them is compatible with type K while the remaining two seem to be TTauri stars. Furthermore, the MIR images indicate the existence of separate circumstellar discs in the K-binary system. NIR colour-colour and colour-magnitude diagrams obtained from 2MASS data are examined to explore the physical properties of the sources and to derive the distribution of J luminosities. There is a clear decrease in luminosity and thus in stellar mass when going from South to North. Likewise, there is an anti-correlation between ClassI and II objects in both regions: while OMC2 contains twice as much ClassII objects compared to ClassI, the situation is reversed in OMC3.