Resolved submillimeter observations of the HR 8799 and HD 107146 debris disks

We present 880 μm Submillimeter Array observations of the debris disks around the young solar analog HD107146 and the multiple-planet host star HR8799, at an angular resolution of 3″ and 6″, respectively. We spatially resolve the inner edge of the disk around HR8799 for the first time. While the data are not sensitive enough (with rms noise of 1mJy) to constrain the system geometry, we demonstrate that a model by Su et al. based on the spectral energy distribution (SED) with an inner radius of 150AU predicts the spatially resolved data well. Furthermore, by modeling simultaneously the SED and visibilities, we demonstrate that the dust is distributed in a broad (of order 100AU) annulus rather than a narrow ring. We also model the observed SED and visibilities for the HD107146 debris disk and generate a model of the dust emission that extends in a broad band between 50 and 170AU from the star. We perform an a posteriori comparison with existing 1.3mm CARMA observations and demonstrate that a smooth, axisymmetric model reproduces all of the available millimeter-wavelength data well.