Ultraviolet Radiation and Circumstellar Environments
نویسندگان
چکیده
We discuss the nature of the photoevaporating circumstellar disks in the Orion Nebula. The structure of thermally driven neutral and ionized ow from the disks is derived through a simple, spherical model. Evaporation ows are self-regulating, and from the estimated mass loss rates we show that it is possible to estimate the present disk masses. Two-dimensional eeects are discussed qualitatively and proposed as the mechanism for the creation of observed tails. Disk magnetic elds may be able to collimate the evaporation ows, giving rise to bipolar lobes; HST 10 provides an observed example of an evaporating system with bipolar lobes symmetric about the disk.
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