Abstract
The evolution and appearance of circumstellar disks in star forming regions can be influenced strongly by the radiation from nearby hot stars. UV radiation heats the outer layers of the disk and induces expansion up to escape velocities. Hollenbach, Yorke, & Johnstone (2000) identify this ``photoevaporation'' process as a principal, if not the most important, disk destruction mechanism. Here, we describe the results of numerical simulations of the evolution of protostellar disks and their surroundings under the influence of external UV radiation. In order to assess the role of central stellar winds, we have included the effects of an isotropic wind in the numerical models.
