Disks, microjets, windblown bubbles, and outflows in the Orion Nebula

New deep narrowband images of the Orion Nebula obtained with WFPC2 on the H ubble Space Telescope (HST) and spectra taken with the HIRES spectrometer a t the Keck Observatory are presented. We report eight new circumstellar dis ks seen in silhouette against the background nebular light and about 30 dar k disks embedded within the bright proplyds rimmed by ionization fronts. De ep narrowband lambda 6300 Angstrom images reveal skins of glowing [O I] emi ssion associated with several disks embedded within bright proplyds. [O I] emission also surrounds one dark disk not surrounded by an ionization front ; this object may be embedded within the photon-dominated, mostly neutral r egion behind the ionization front of the Or ion Nebula. The intensity and m orphology of the CO I] emission provides support for the photon-dominated-r egion models of externally irradiated circumstellar disks in which soft UV powers photoablation of the disk surface. Dozens of outflows powered by you ng stars have been discovered on the new images. More than 20 stellar jets emerge from the externally irradiated circumstellar disks or their associat ed young stars embedded within the Nebula. Most are one-sided (monopolar) s ubarcsecond-scale microjets, too small to be seen on ground-based images ag ainst the bright background nebular light. Additionally, wide-angle winds f rom 10 young stars in the outskirts of the Nebula power large-scale bow sho cks facing the Trapezium OB stars. These shocks may be produced by wind-win d interactions where the T-Tauri winds interact with the outflow of plasma from the core of M42. The largest such structure, associated with the star LL Ori, contains a number of compact high-proper-motion clumps moving almos t tangentially to the bow shock. The new data are combined with older HST images to determine proper motions for many nebular features. Neither the LL Ori type bow shocks in the outsk irts of the nebula nor the H alpha + [O III] arcs that surround many proply ds near the Trapezium show measurable proper motions and are therefore stat ionary structures. However, most other bow-shaped features not centered on young stars exhibit large proper motions, with velocities ranging from 50 t o 300 km s(-1). The sources of many of these moving features remain unknown . The proper-motion survey of the nebular core reveals the presence of abou t a dozen new large-scale (>0.1 pc) outflow complexes. Many of these new ou tflows originate from the vicinity of the high-luminosity OMC-1S infrared a nd submillimeter source complex located southwest of the Trapezium. These s upersonic features provide evidence that stellar outflows inject large amou nts of kinetic energy into the nebula. However, a quantitative analysis ind icates that their total power is small compared with the power in the plasm a flowing away from the main nebular ionization front.