Physics Commons^™

Orion's Bar: Physical Conditions Across The Definitive H+/H0/H2 Interface, E. W. Pellegrini, J. A. Baldwin, Gary J. Ferland, G. Shaw, S. Heathcote

Physics and Astronomy Faculty Publications

Previous work has shown the Orion Bar to be an interface between ionized and molecular gas, viewed roughly edge-on, which is excited by the light from the Trapezium cluster. Much of the emission from any star-forming region will originate from such interfaces, so the Bar serves as a foundation test of any emission model. Here we combine X-ray, optical, infrared (IR), and radio data sets to derive emission spectra along the transition from H⁺ to H⁰ to H₂ regions. We then reproduce the spectra of these layers with a simulation that simultaneously accounts for the detailed microphysics …