Silicon Monoxide Observations Reveal a Cluster of Hidden Compact Outflows in the OMC 1 South Region

Abstract

We present high angular resolution (2.8''{\times}1.7'') SiO J=5--{\gt}4,v=0 line observations of the OMC 1S region in the Orion Nebula madeusing the Submillimeter Array (SMA). We detect for the first timea cluster of four compact bipolar and monopolar outflows that showhigh-, moderate-, and low-velocity gas and appear to be energizedby millimeter and infrared sources associated with this region. TheSiO molecular outflows are compact ({\lt}3500 AU), and in most ofthe cases, they are located very close to their exciting sources.We thus propose that the SiO thermal emission is tracing the youngestand most highly excited parts of the outflows that cannot be detectedby other molecules. Moreover, since the ambient cloud is weak inthe SiO line emission, these observations can reveal flows that inother molecular transitions will be confused with the ambient velocitycloud emission. Analysis of their position-velocity diagrams showthat some components of these outflows may be driven by wide-anglewinds very close to the exciting object. Finally, we find that someof these SiO outflows seem to be the base of powerful Herbig-Harojets and large-scale molecular flows that emanate from a few arcsecondsaround this zone. In particular, we find a strongly excited SiO bipolaroutflow with a P.A. of ~100{\deg} that is likely energized bythe luminous (~3{\times}10^{3} L_{solar}) infrared protostar``B'' and could be the base of the remarkable object HH 269.