VLA Detection of Protostars in OMC-2/3

Abstract

The OMC-2/3 molecular clouds contain one of the highest concentrations of protostars known in nearby molecular clouds. We have observed an area of about 6@ ] 15@ (0.8 pc ] 2 pc) covering the OMC-2/3 region with the Very Large Array in the D conÐguration at 3.6 cm, matching well the area of a recent 1300 km survey. We detected 14 sources, of which it is highly probable that 11 sources are either protostars or very young stars. This testiÐes to the star-forming activity and extreme youth of the OMC-2/3 region. The 3.6 cm Ñux is free-free emission probably due to shocks in outÑowing material. Three of the sources are extended even with the relatively low resolution of the present observations, and two of these may be collimated radio jets. The large fraction of submillimeter continuum sources that have a radio continuum counterpart is evidence that outÑow is already common at the very earliest evolutionary stages. No relation is found between the radio continuum Ñux and the 1300 km Ñux of the associated submillimeter dust clumps.