11112( 3) - 05/11/07 06:50 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11112 Version: 3 Check-in Time: 11-May-2007 10:49:44 STScI Edit Number: 0 Title The Collisional Ring Galaxy NGC922 ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Gerhardt R. Meurer The Johns Hopkins University CoI: Dr. Kenji Bekki University of New South Wales N CoI: Dr. Anne Pellerin Space Telescope Science Institute N CoI: Prof. Debra Elmegreen Vassar College N CoI: Ms. Oeiwei Ivy Wong University of Melbourne N CoI: Dr. Patricia Knezek National Optical Astronomy Observatories, N AURA ------------------------------------------------------------------------------------ Abstract We request WFPC2 images of the newly recognized collisional ring galaxy NGC922 which will become the nearest such system observed by HST. These will be used to get a clear understanding of the geometry of the interaction and the induced star formation in this system. Quantitive modeling of the colors of the star clusters and stellar populations will be used to constrain the star formation history of the system. They will also be used to test the "infant mortality" scenario for star cluster evolution. The derived population ages will test predictions of how star formation evolves in the various components (ring, core, spokes) of collisional rings, and will improve our own simulations of this system. These will be used to determine the final fate of the stars formed in the present burst - some will end up in a central bar or bulge while others will become part of a thickened disk. By analogy this will tell us how similar collisions enrich stellar populations in the early universe. This is especially relevant since the number density of collisional rings increases rapidly with redshift. ------------------------------------------------------------------------------------ 11112( 3) - 05/11/07 06:50 - [ 2] Observations Description ------------------------ We will observe NGC922 in F300W (3 orbits), F439W, (2 orbits), F547M (2orbits) and F814W (2 orbits). The observations will be split between two mosaic positions offset by 40" in order to observe the entire 104" diameter ring with WF2 and WF3. Three exposures will be taken at each mosaic position, with each exposure being shifted by a small dither offset. Both the mosaic and dither offsets are achieved through POS-TARG commands. The position of NGC922 has been adjusted from that given in the phase I proposal in order to conform better with the geometric center of the ring. This allows the pos-targ commands to be robust to the roll-angle that is employed. The observations are split into two visits which are constrained to have the same orient. Ideally they should be scheduled back to back. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11112( 3) - 05/11/07 06:50 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC922 GALAXY, DISK, RA=02H25M3.7400S +/- 1", DEC=- J2000 V = V = 12.12+/-0.13 INTERACTING GALAXY, 24D47'24.80" +/- 1" 3083.0 R = 11.94 +/- 0.05 ABmag RING, STARBURST Reference Frame: ICRS Comments: Distance = 43 Mpc from the radial velocity using the Mould (2000, ApJ, 529, 786) multi-attractor model. 11112( 3) - 05/11/07 06:50 - [ 4] Visit: 01 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: All F300W and F439W observations will be taken in this visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC922 WFPC2 IMAGE WF3-FIX F300W CR-SPLIT=NO 1 1100 S POS TARG 22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC922 WFPC2 IMAGE WF3-FIX F300W CR-SPLIT=NO 1 1100 S POS TARG 22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC922 WFPC2 IMAGE WF3-FIX F300W CR-SPLIT=NO 1 1100 S POS TARG 22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC922 WFPC2 IMAGE WF3-FIX F300W CR-SPLIT=NO 1 1100 S POS TARG -22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC922 WFPC2 IMAGE WF3-FIX F300W CR-SPLIT=NO 1 1100 S POS TARG -22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC922 WFPC2 IMAGE WF3-FIX F300W CR-SPLIT=NO 1 1100 S POS TARG -22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC922 WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 600 S POS TARG 22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC922 WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 600 S POS TARG 22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC922 WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 600 S POS TARG 22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC922 WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 600 S POS TARG -22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC922 WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 600 S POS TARG -22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC922 WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 600 S POS TARG -22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC922 1 WFPC2 IMAGE WF3-FIX F300W none none none none 1 N/A NGC922 2 WFPC2 IMAGE WF3-FIX F300W none none none none 1 N/A NGC922 3 WFPC2 IMAGE WF3-FIX F300W none none none none 2 N/A NGC922 4 WFPC2 IMAGE WF3-FIX F300W none none none none 2 N/A NGC922 5 WFPC2 IMAGE WF3-FIX F300W none none none none 3 N/A NGC922 6 WFPC2 IMAGE WF3-FIX F300W none none none none 3 N/A NGC922 7 WFPC2 IMAGE WF3-FIX F439W none none none none 4 N/A NGC922 8 WFPC2 IMAGE WF3-FIX F439W none none none none 4 N/A NGC922 9 WFPC2 IMAGE WF3-FIX F439W none none none none 4 N/A NGC922 10 WFPC2 IMAGE WF3-FIX F439W none none none none 5 N/A NGC922 11 WFPC2 IMAGE WF3-FIX F439W none none none none 5 N/A 11112( 3) - 05/11/07 06:50 - [ 5] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC922 12 WFPC2 IMAGE WF3-FIX F439W none none none none 5 N/A 11112( 3) - 05/11/07 06:50 - [ 6] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENT AS 01 On Hold Comments: Additional Comments: All F547M, and F814W observations are obtained in this visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC922 WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 1 600 S POS TARG 22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC922 WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 1 600 S POS TARG 22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC922 WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 1 600 S POS TARG 22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC922 WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 1 600 S POS TARG -22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC922 WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 1 600 S POS TARG -22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC922 WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 1 600 S POS TARG -22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC922 WFPC2 IMAGE WF3-FIX F547M CR-SPLIT=NO 1 600 S POS TARG -22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC922 WFPC2 IMAGE WF3-FIX F547M CR-SPLIT=NO 1 600 S POS TARG -22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC922 WFPC2 IMAGE WF3-FIX F547M CR-SPLIT=NO 1 600 S POS TARG -22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC922 WFPC2 IMAGE WF3-FIX F547M CR-SPLIT=NO 1 600 S POS TARG 22, 20 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC922 WFPC2 IMAGE WF3-FIX F547M CR-SPLIT=NO 1 600 S POS TARG 22.498, 23.984 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC922 WFPC2 IMAGE WF3-FIX F547M CR-SPLIT=NO 1 600 S POS TARG 22.996, 27.968 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC922 1 WFPC2 IMAGE WF3-FIX F814W none none none none 1 N/A NGC922 2 WFPC2 IMAGE WF3-FIX F814W none none none none 1 N/A NGC922 3 WFPC2 IMAGE WF3-FIX F814W none none none none 1 N/A NGC922 4 WFPC2 IMAGE WF3-FIX F814W none none none none 2 N/A NGC922 5 WFPC2 IMAGE WF3-FIX F814W none none none none 2 N/A NGC922 6 WFPC2 IMAGE WF3-FIX F814W none none none none 2 N/A NGC922 7 WFPC2 IMAGE WF3-FIX F547M none none none none 3 N/A NGC922 8 WFPC2 IMAGE WF3-FIX F547M none none none none 3 N/A NGC922 9 WFPC2 IMAGE WF3-FIX F547M none none none none 3 N/A NGC922 10 WFPC2 IMAGE WF3-FIX F547M none none none none 4 N/A NGC922 11 WFPC2 IMAGE WF3-FIX F547M none none none none 4 N/A 11112( 3) - 05/11/07 06:50 - [ 7] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC922 12 WFPC2 IMAGE WF3-FIX F547M none none none none 4 N/A 11112( 3) - 05/11/07 06:50 - [ 8] Summary Form for Proposal 11112 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WF3-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 22, 20; POS TARG 22.498, 23.984; POS TARG 22.996, 27.968; POS TARG -22, 20; POS TARG -22.498, 23.984; POS TARG -22.996, 27.968; SAME ORIENT AS 01; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F300W F439W F814W F547M ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC922 ------------------------------------------------------------------------------------------------------------------------------------