Infrared and Millimeter Observations of Inner and Outer Disks around Young Stars
          Jenny Patience, Caltech
          Rachel Akeson, MSC/Caltech
          Anneila Sargent, Caltech
          Eric Jensen, Swarthmore

          Observations of disk material surrounding young stars determine the early environmental conditions that influence the development of planetary systems and provide constraints on theoretical models of star and planet formation. At infrared wavelengths, we are exploiting the exceptional angular resolution of the Keck interferometer to resolve the hot inner disks of classical and weak-lined T Tauri stars at sub-AU scales. With the Owens Valley Millimeter Array (OVRO) we are targeting Class I and Class II young binaries in Taurus and Ophiuchus to determine the distribution and evolution of cool dust in the outer disks.

The K-band Keck interferometry measurements of several pre-Main Sequence stars show calibrated squared visibilities significantly less than unity, indicating spatially resolved sources. By modeling the visibility as arising from an unresolved star and a resolved disk the size of the inner disk can be estimated. The inferred sizes are more consistent with disk models incorporating a puffed-up inner edge at the dust destruction radius than standard flared disk models.

The OVRO 3mm continuum maps of the Ophiuchus binaries reveal that the dust emission is dominated by the primary, even at the Class I stage. The circumprimary disks have masses that are comparable to the Minimum Mass Solar Nebula and show evidence for grain growth. The nondetection of massive secondary disks suggests a dissipation timescale that may negatively impact planet formation. One Ophiuchus secondary is detected in line emission with the unique combination of a CO gas disk without a corresponding dust disk detection