The Structure and Appearance of Protostellar Accretion Disks: Limits on Disk Flaring

Abstract

Vertical structure models are used to investigate the structure of protostellar, α-law, accretion disks. Conditions investigated cover a range of mass fluxes (10-9 to 10-5 M☉ yr-1), viscous efficiencies (α = 10-2 and 10-4), and stellar masses (0.5-3 M☉). Analytic formulae for midplane temperatures, optical depths, and volume and surface densities are derived and are shown to agree well with numerical results. The temperature dependence of the opacity is shown to be the crucial factor in determining radial trends. We also consider the effect on disk structure of illumination from a uniform field of radiation such as might be expected of a system immersed in a molecular cloud core or other star-forming environment: Tamb = 10, 20, and 100 K. Model results are compared to Hubble Space Telescope observations of HH30 and the Orion proplyds.