Thermal-IR Detection of Optical Outflow Sources in OMC1 South

摘要

We present the first thermal-infrared imaging photometry for several embeddedsources in the OMC1 South cloud core in the Orion nebula, and propose that someof these drive optical Herbig-Haro jets emerging from the region.Thermal-infrared images at 8.8 and 11.7 micron obtained at Gemini South show ahandful of sources in OMC1-S with no visual-wavelength counterparts, although afew can be seen in recent near-infrared data. For the three brightestmid-infrared sources, we also present 18.75 micron photometry obtained with theKeck telescope. The most prominent blueshifted outflows in the Orion nebula atvisual wavelengths such as HH202, HH203/204, HH529, and HH269 all originatefrom OMC1-S. The brightest infrared source in OMC1-S at 11.7 micron is locatedat the base of the prominent jet that powers HH202 and is likely to be thesought-after driver of this outflow. The second brightest infrared source islocated at the base of the HH529 jet. We consider the possibility thatHH203/204 and HH269 trace parts of a single bent outflow from thethird-brightest infrared source. While there may be some lingering ambiguityabout which infrared stars drive specific jets, there is now a sufficientnumber of embedded sources to plausibly account for the multiple outflows fromOMC1-S.