Coronagraphic imaging with the Near-Infrared Camera and Multiobject Spectrometer on the Hubble Space Telescope reveals a large, approximately 400 AU (4&arcsec;) radius, circumstellar disk around the Herbig Ae/Be star HD 141569. A reflected light image at 1.1 µm shows the disk oriented at a position angle of 356&j0;+/-5&j0; and inclined to our line of sight by 51&j0;+/-3&j0;; the intrinsic scattering function of the dust in the disk makes the side inclined toward us, the eastern side, brighter. The disk flux density peaks 185 AU (1&farcs;85) from the star and falls off to both larger and smaller radii. A region of depleted material, or a gap, in the disk is centered 250 AU from the star. The dynamical effect of one or more planets may be necessary to explain this morphology.

We report high-resolution imaging of the ultraluminous infrared galaxy Arp 220 at 1.1, 1.6, and 2.22 mm with the Near-Infrared Camera and Multiobject Spectrometer on the Hubble Space Telescope. The diffraction-limited images at 0Љ .1-0Љ .2 resolution clearly resolve both nuclei of the merging galaxy system and reveal for the first time a number of luminous star clusters in the circumnuclear envelope. The morphologies of both nuclei are strongly affected by dust obscuration, even at 2.2 mm: the primary nucleus (west) presents a crescent shape, concave to the south, and the secondary (eastern) nucleus is bifurcated by a dust lane with the southern component being very reddened. In the western nucleus, the morphology of the 2.2 mm emission is most likely the result of obscuration by an opaque disk embedded in the nuclear star cluster. The morphology of the central starburst cluster in the western nucleus is consistent with either a circumnuclear ring of star formation or a spherical cluster with the bottom half obscured by the embedded dust disk. Comparison of centimeter-wave radio continuum maps with the near-infrared images suggests that the radio nuclei lie in the dust disk on the west and near the highly reddened southern component of the eastern complex. The radio nuclei are separated by 0Љ .98 (corresponding to 364 pc at 77 Mpc), and the half-widths of the infrared nuclei are ∼0Љ .2-0Љ .5. At least eight unresolved infrared sources-probably globular clusters-are also seen in the circumnuclear envelope at radii of 2Љ-7Љ. Their nearinfrared colors do not significantly constrain their ages.

Mid-infrared observations of the central source of NGC 1068 have been obtained with a spatial resolution in the deconvolved image of (D7 pc). The central source is extended by D1A in the north-0A .1 south direction but appears unresolved in the east-west direction over most of its length. About 2/3 of its Ñux can be ascribed to a core structure that is itself elongated north-south and does not show a distinct unresolved compact source. The source is strongly asymmetric, extending signiÐcantly farther to the north than to the south. The morphology of the mid-infrared emission appears similar to that of the radio jet and has features which correlate with the images in [O III]. Its 12.5È24.5 km color temperature ranges from 215 to 260 K and does not decrease smoothly with distance from the core. Silicate absorption is strongest in the core and to the south and is small in the north. The core, apparently containing 2/3 of the bolometric luminosity of the inner 4A diameter area, may be explained by a thick, dusty torus near the central active galactic nucleus (AGN) viewed at an angle of D65¡ to its plane. There are, however, detailed difficulties with existing models, especially the narrow east-west width of the thin extended mid-infrared "" tongue ÏÏ to the north of the core. We interpret the tongue as reprocessed visual and ultraviolet radiation that is strongly beamed and that originates in the AGN.

Observations for seven infrared luminous starburst galaxies are reported in the midinfrared from 8 -18 µm using the Keck Telescopes with spatial resolution approaching the diffraction limit . All of the galaxies observed show evidence of strong interactions based on optical morphologies. For these galaxies, a substantial fraction, usually more than 50%, of the infrared luminosity is generated in regions ranging in sizes from 100pc -1 Kpc. Nuclear starbursts often dominate the infrared luminosity, but this is not always true. In some galaxies, most notably NGC 6090, substantial infrared luminosity greatly in excess of the nuclear luminosity is generated in regions associated with the physical interaction between two galaxies. The radio emission is a good tracer of the location of high luminosity young stars.The visual/ultraviolet radiation output of the nearby star forming galaxies is dominated by emission from regions that are generally not producing the copious infrared luminosity of the systems. As seen in comparing the mid-infrared and near infrared images of the galaxies observed here, the regions of high infrared luminosity in local galaxies are significantly smaller than the galaxies as a whole. The integrated spectral energy distributions (SEDs) of these galaxies are very different from the SEDs of the regions of star formation. If the SEDs of star-forming regions in these galaxies reflect the SEDs that would be found in forming galaxies at high redshift, we would expect the distant galaxies to be dominated by the mid and far-infrared luminosity output far more than the integrated luminous output of nearby starburst galaxies would suggest.

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