Externally illuminated young stellar objects in the Orion Nebula

Abstract

The Hubble Space Telescope (HST) has detected intense line emission from the ionization fronts that wrap around the residual dense gas surrounding over 50 YSOs born from the Orion Molecular cloud within the last 1 million years. Several of these envelopes have central stars surrounded by highly symmetric silhouettes that may be circumstellar disks seen in absorption against the nebular background. We will review the relevant physical processes that must be considered in evaluating the structure and kinematics of these objects. We also present 7 A.U. resolution UV images of 5 externally illuminated protostellar environments and report the detection of 2.1218 μm molecular hydrogen emission from these objects. Show more