Spectrally dispersed K-band interferometric observations of herbig Ae/Be sources: Inner disk temperature profiles

We use spectrally dispersed near-IR interferometry data to constrain the temperature profiles of sub-AU-sized regions of 11 Herbig Ae/Be sources. We find that a single-temperature ring does not reproduce the data well. Rather, models incorporating radial temperature gradients are preferred. These gradients may arise in a dusty disk, or may reflect separate gas and dust components with different temperatures and spatial distributions. Comparison of our models with broad-band spectral energy distributions suggests the latter explanation. The data support the view that the near-IR emission of Herbig Ae/Be sources arises from hot circumstellar dust and gas in sub-AU-sized disk regions. Intriguingly, our derived temperature gradients appear systematically steeper for disks around higher mass stars. It is not clear, however, whether this reflects trends in relative dust/gas contributions or gradients within individual components.