5799( 0) - 07/18/95 18:01 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5799 Version: ********** Check-in Date: ********** 1.Proposal Title: Planetary Nebular Modeling with the Aid of Existing HST Imagery ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium AR 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Charles Keyes Space Telescope Science Institute CoI: Lawrence Aller University of California, Los Angeles N CoI: Siek Hyung University of California, Los Angeles N ------------------------------------------------------------------------------------ 6. Abstract We propose to rediscuss the existing HST WFPC observations of five planetary nebulae, namely NGC 7027, NGC 2440, Hb 12, IC 418, and IC 4997. These images were obtained in pre-servicing GO and GTO programs. Most of the images are of very good quality, and are well-suited for our investigation. We propose to use the HST high spatial resolution images to determine the sub-arcsecond geometrical structure of these PN for which we have obtained high quality high spectral resolution optical data with the Hamilton echelle CCD spectrograph at Lick Observatory. We possess state-of-the-art modeling techniques for the thermal, ionization, and physical structure of low-to-moderate density astrophysical plasmas. On the basis of the HST- derived small-scale structure we will construct new theoretical thermal and ionization models with our enhanced density contrast modeling technique in order to derive highly improved chemical abundances. This project parallels our own observing proposal, submitted for Cycle 5 under the title ``HST Imagery of Compact and Axi-symmetrical Planetary Nebulae''. ------------------------------------------------------------------------------------ Observations Description ------------------------ Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 5799( 0) - 07/18/95 18:01 - [ 2] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5799( 0) - 07/18/95 18:01 - [ 3] Summary Form for Proposal 5799 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category AR ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------