NICMOS 2 Micron Continuum and H[TINF]2[/TINF] Images of OMC-1

Abstract

The core of OMC-1 has been imaged with the Near-Infrared Camera and Multiobject Spectrometer (NICMOS) on board the Hubble Space Telescope at 02 resolution in 1% filters at 2.12 and 2.15 μm, revealing intricate structures in both continuum and shocked molecular hydrogen line emission. Numerous H2-emitting clumps surrounding the BN/KL region have been resolved for the first time, several of which exhibit prototypical bow-shock morphologies with V-shaped tips. We interpret these to be lower excitation analogs of similar structures ~2' northwest of the core observed with ground-based telescopes. Many of the elongated H2 structures and bow-shock features appear to radiate outward from a region within a few arcseconds of radio source I, which suggests that the H2 energetics are dominated by one or more outflow sources in this region. However, the orientations of some features are unrelated to this apparent outflow pattern. The deeply embedded, suspected outflow source I remains undetected at 2 μm, although two faint new continuum sources have been detected within ~1'' of it. The newly resolved H2 features with bow-shock morphologies are located in regions previously identified as bow shocks by highly blueshifted components in their line profiles. In contrast, regions of H2 emission that are diffuse in the NICMOS image have broad, smooth line profiles. Several continuum features have an arclike appearance, which suggests interactions of winds with the ambient medium. At least 40 stellar or protostellar continuum sources have been detected, including at least one proplyd and four pairs of binary stars.