We have mapped [Ne II] (12.8um) and [S IV] (10.5um) emission from W51 IRS 2 with TEXES on Gemini North, and we compare these data to VLA free-free observations and VLT near-infrared images. With 0.5" spatial and 4 km/s spectral resolution we are able to separate the ionized gas into several components: an extended H II region on the front surface of the molecular cloud, several embedded compact H II regions, and a streamer of high velocity gas. We interpret the high velocity streamer as a precessing or fan-like jet, which has emerged from the molecular cloud into an OB star cluster where it is being ionized.
@article{arxiv.astro-ph/0702327,
title = {W51 IRS 2: A Massive Jet Emerging from a Molecular Cloud into an H II Region},
author = {J. H. Lacy and D. T. Jaffe and Q. Zhu and M. J. Richter and M. A. Bitner and T. K. Greathouse and K. Volk and T. R. Geballe and D. M. Mehringer},
journal= {arXiv preprint arXiv:astro-ph/0702327},
year = {2010}
}