VELOCITY PROFILES OF HIGH-EXCITATION MOLECULAR-HYDROGEN LINES

Profiles of three lines of molecular hydrogen near 2.2 μm, originating from widely spaced energy levels, have been measured at a resolution of 32 km s-1 at Peak 1 in the Orion molecular outflow. The three lines [1-0 5(1), 2-1 5(1) and 3-2 5(3)] are found to have identical profiles. This result rules out any significant contribution to the population of the higher energy levels of molecular hydrogen at Peak 1 by fluorescence, is inconsistent with multiple C-shock models which produce higher excitation temperatures at larger shock velocities, and is generally consistent with emission from multiple J-type shocks. © Royal Astronomical Society • Provided by the NASA Astrophysics Data System.