Program: GN-2009B-Q-37

We propose to use NIRI with LGS + Altair on Gemini North to build a diffraction-limited mosaic of the entire OMC1 outflow in the 2.12 $\mu$m H$_2$ and 1.64 $\mu$m [Fe II] lines and in the K-short filter. The OMC1 outflow is the nearest example of a powerful mass ejection from a system of forming massive stars. The origin of this remarkable outflow may shed critical light on the physical processes involved in the formation of massive stars, the interactions of such stars with their environment, and the ejection of high-velocity run-away stars. We will combine the 0.1\arcsec\ resolution images with archived HST and ground-based images to measure proper motions of shocks with unprecedented precision to determine the point of origin of the OMC 1 outflow. This will test whether the outflow is powered by continuous energy injection or an explosion, possibly triggered by the dynamical decay of a non-hierarchical massive star system that ejected the IR and radio stars BN, I, and n with speeds of 10 to 30 km~s$^{-1}$ 500 years ago (Menten \& Reid 1995, Gomez et al. 2005). This program requires the observation of 18 fields, only 5 were observed in 2008 as part of Band 1 program 2008B-0468 (= GN-2008B-Q-1) on Gemini North. We propose to complete this project in 2009 by observing the remaining fields. Re-observation of the 5 fields will enable proper motion determinations in less than a cooling time.