10653( 1) - 04/05/05 12:19 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10653 Version: 1 Check-in Date: 05-Apr-2005 16:19:21 1.Proposal Title: Dynamical flows in PNe: interpreting HST images on a physical basis ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance AR 14 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Gary J. Ferland University of Kentucky CoI: Dr. C. Robert O'Dell Vanderbilt University N CoI: Mr. Nicholas P. Abel University of Kentucky N ------------------------------------------------------------------------------------ 6. Abstract This theory proposal requests support to develop a combination of chemistry and hydrodynamics, and apply it to the analysis and interpretation of HST observations of knots in the Helix. They offer a laboratory to understand flows from molecular condensations into a low-density ionized medium, and so have implications for other environments, such as H II regions and Starbursts. The project involves developing the chemistry and dynamics in the spectral simulation code Cloudy. Cloudy is widely used across the astronomical community, so the proposed developments will have broad application. Recent NICMOS observations detail aspects of the flow from the molecular core, where the gas is surprisingly warm, into the ionized region, where STIS and WFPC2 measure the surface brightness and relative intensities of emission lines. We will make the following improvements: The heavy element chemical network (including CO) and a complete model of molecular hydrogen will be integrated into our treatment of dynamics. Our previous work had only included atomic and ionized regions. We will consider strongly divergent flows, as seen in the Helix; our previous work used only a plane-parallel geometry. We will use the improved code to create evolutionary grids that follow changes as the system ages. Our goals are to determine the mass, mass-loss rate, and lifetime of the knots, and identify the mechanisms responsible for their current physical state. ------------------------------------------------------------------------------------ 10653( 1) - 04/05/05 12:19 - [ 2] Summary Form for Proposal 10653 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category AR ------------------------------------------------------------------------------------------------------------------------------------