Resolved Inner Disks around Herbig Ae/Be Stars

We have observed 14 Herbig Ae/Be sources with the long-baseline near-IRPalomar Testbed Interferometer, All except two sources are resolved at 2.2 um,with angular sizes generally <5 mas. We determine the size scales andorientations of the 2.2 um emission using various models: uniform disks,Gaussians, uniform rings, flat accretion disks with inner holes, and flareddisks with puffed-up inner rims; 7 objects display significantly inclinedmorphologies, generally compatible with the outer disk geometries inferred frommillimeter interferometric observations, implying that HAEBE disks are notsignificantly warped. Using the derived inner disk sizes and inclinations, wecompute the spectral energy distributions for two simple physical disk models,and compare these with observed SEDs compiled from the literature and newnear-IR photometry. While geometrically flat accretion disk models areconsistent with the data for the earliest spectral types in our sample (MWC297, V1685 Cyg, and MWC 1080), the later-type sources are explained betterthrough models incorporating puffed-up inner disk walls; this may indicatedifferent accretion mechanisms for early and late-type Herbig Ae/Be stars.Comment: 54 pages, including 16 figures. Accepted for publication in the Astrophysical Journal (October 2004 issue