Radiation Transfer Modeling of Circumstellar Disks

Be stars are hot, massive stars that have gaseous circumstellar disks.  Aproposed model for creating these disks is vicous 
decretion, in which material is ejected from the star, placed into orbit, and spread outward by viscous diffusion.  In this talk, I 
will review the basic processes for how these disksproduce the observed IR excess emission, linear polarization, as well 
as spectroscopic line formation.  Finally I will discuss how we are using 3-D NLTE Monte Carlo simulations to predict the 
various observations, and how we are employing high resolution imaging techniques like spectroastrometry 
and optical/near-IR interferometry to directly measure the disk kinematics.  The results of these tests provide strong support 
for the viscous decretion disk model.