Recent observations by the Spitzer Space Telescope have hinted at the possible ubiquity of abundant warm water vapor in the terrestrial planet-forming zones of protoplanetary disks around young stars. Whilst chemically productive, these disks are dust-poor and susceptible to the destructive ultraviolet radiation field emanating from the central star. It is therefore important to understand how this water survives. We present a new model in which the opacity due to incipient gas-phase water production in the warm disk leads to a runaway process of self-shielding and widespread water formation. Our model adequately explains the observed abundances of both warm H2O and OH. The total water vapor produced amounts to thousands of oceans-worth within the inner few AU. Shielding by water helps create a sanctuary in which organic chemistry and other prebiotic processes may occur during the era of planet-formation.

Water self-shielding in protoplanetary disks

239th National Meeting (2010)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.