Spectral Energy Distributions of Passive T Tauri and Herbig Ae Disks: Grain Mineralogy, Parameter Dependences, and Comparison with Infrared Space Observatory LWS Observations

摘要: We improve upon the radiative, hydrostatic equilibrium models of passive circumstellar disks constructed by Chiang & Goldreich. New features include (1) an account for a range particle sizes, (2) employment laboratory-based optical constants representative grain materials, and (3) numerical solution equations radiative within original two-layer (disk surface plus disk interior) approximation. systematically explore how spectral energy distribution (SED) face-on depends on size distributions, geometries densities, stellar photospheric temperatures. Observed SEDs three Herbig Ae two T Tauri stars, including spectra from Long Wavelength Spectrometer (LWS) aboard Infrared Space Observatory (ISO), are fitted with our models. Silicate emission bands optically thin, superheated layers appear in nearly all systems. Water ice LWS coolest stars. excesses several sources consistent significant vertical settling grains. While this work furnishes further evidence that reprocessing starlight flared adequately explains origin infrared-to-millimeter wavelength young we emphasize explicit calculations SED alone does not provide sufficient information to constrain sizes masses uniquely.