9443( 3) - 04/18/02 09:56 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9443 Version: 3 Check-in Date: 18-Apr-2002 09:55:43 1.Proposal Title: Calibration of the Geometric Distortion of ACS ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Ivan King University of California - Berkeley CoI: Dr. Jay Anderson University of California, Berkeley N ------------------------------------------------------------------------------------ 5. Abstract We propose to calibrate the geometric distortion of the WFC and HRC of ACS, using the state-of-the-art techniques that we have developed for WFPC2. We are confident that we can measure the distortion to at least an order or magnitude higher accuracy than is called for in the ACS Manual. We will use the images that are to be taken in GO-9028 and will re- image the field used there at different orientation and through different filters, so as to improve knowledge of the skewness of the field and the dependence of distortion on wavelength. Our results will not only enhance the accuracy of our own proposed proper-motion work in star clusters; they will greatly increase the accuracy of sparse-field astrometry by others, such as solar-sytem and extragalactic work. ------------------------------------------------------------------------------------ 9443( 3) - 04/18/02 09:56 - [ 2] Observations Description ------------------------ We use 2 orbits for WFC and 2 for HRC, one orbit to image the field of GO-9028 at an orthogonal orientation, and the other orbit to observe the field through a variety of other filters. An RPS2 run on the exposures of GO-9028 tells us that five 60s exposures will fit into an orbit. That is what we will use for the repeat at a 90D rotation. (Given our own choice we would have chosen a longer exposure time, so as to have more stars, but at this point we believe that we will do best to repeat the earlier observations closely in everything except orientation.) Similarly, RPS2 tells us that we can get a 200s exposure, followed by 4 more of 350s each, into a single orbit. In the filter comparison we can use the shorter exposure for F606W, which has a high throughput. Real Time Justification ----------------------- Required orientation will restrict the scheduling window, but not severely. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9443( 3) - 04/18/02 09:56 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC104 CALIBRATION, SPATIAL RA=00H 24M 5S +/- 1", DEC=-72D J2000 V = 19.5+/-0.5 DISTORTION TEST, 4' 50" +/- 1", PLATE-ID=01X5 STELLAR CLUSTER, GLOBULAR CLUSTER Coordinate Source: GSC_SURVEY_PLATE Comments: Position is chosen so as to cover same field as central exposure of 9028, but at 90D rotation. 9443( 3) - 04/18/02 09:56 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ON HOLD ORIENT 279D TO 279D BEFORE 01-Sep-2002 On Hold Comments: Need to specify ORIENT at 90D from corresponding exposures in 9028, after that proposal is taken. That ORIENT will be available about 3 months after 9028 is taken. Additional Comments: Results from this proposal will be needed by many other ACS observers, so it should be taken as early as possible (provided only that it can reach the needed ORIENT, 90D from that of 9028). Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO 1 60 S C ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO 1 60 S POS TARG 0.272, 0.2472 C ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO 1 60 S POS TARG -0.2720,-0.2720 C ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO 1 60 S POS TARG 0.4945, 0.5192 C ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO 1 60 S POS TARG -1.0137, 0.9890 C ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC104 ACS/WF ACCUM WFC F606W CR-SPLIT=NO,GAIN=2 1 100 S C ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO,GAIN=2 1 150 S C ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC104 ACS/WF ACCUM WFC F555W CR-SPLIT=NO,GAIN=2 1 150 S C ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC104 ACS/WF ACCUM WFC F435W CR-SPLIT=NO,GAIN=2 1 150 S C ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC104 ACS/WF ACCUM WFC F814W CR-SPLIT=NO,GAIN=2 1 150 S C ------------------------------------------------------------------------------------------------------------------------------------ 9443( 3) - 04/18/02 09:56 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ON HOLD SCHED 40% SAME ORIENT AS 01 BEFORE 01-Sep-2002 On Hold Comments: Need to specify ORIENT at 90D from corresponding exposures in 9028, after that proposal is taken. That ORIENT will be available about 3 months after 9028 is taken. Additional Comments: Results from this proposal will be needed by many other ACS observers, so it should be taken as early as possible (provided only that it can reach the needed ORIENT, 90D from that of 9028). Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S C ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG 0.1479, 0.1345 C ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG -0.1479,-0.1479 C ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG 0.2690, 0.2824 C ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG -0.4438, 0.4304 C ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG 0.4304,-0.4438 C ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG 0.7478, 0.0350 C ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG -0.0350,-0.7478 C ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG 0.0215, 1.2239 C ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO 2 60 S POS TARG -1.2239, 0.0215 C ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC104 ACS/HR ACCUM HRC F250W CR-SPLIT=NO,GAIN=4 1 230 S C ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC104 ACS/HR ACCUM HRC F606W CR-SPLIT=NO,GAIN=4 1 350 S C ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC104 ACS/HR ACCUM HRC F475W CR-SPLIT=NO,GAIN=4 1 350 S C ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC104 ACS/HR ACCUM HRC F555W CR-SPLIT=NO,GAIN=4 1 350 S C ------------------------------------------------------------------------------------------------------------------------------------ 9443( 3) - 04/18/02 09:56 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC104 ACS/HR ACCUM HRC F435W CR-SPLIT=NO,GAIN=4 1 350 S C ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC104 ACS/HR ACCUM HRC F814W CR-SPLIT=NO,GAIN=4 1 350 S C ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC104 ACS/HR ACCUM HRC F330W CR-SPLIT=NO,GAIN=4 1 350 S C ------------------------------------------------------------------------------------------------------------------------------------ 18 NGC104 ACS/HR ACCUM HRC F250W CR-SPLIT=NO,GAIN=4 1 460 S C ------------------------------------------------------------------------------------------------------------------------------------ 9443( 3) - 04/18/02 09:56 - [ 7] Summary Form for Proposal 9443 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC HRC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO GAIN=2 GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ON HOLD ORIENT 279D TO 279D BEFORE 01-Sep-2002 POS TARG 0.272, 0.2472 POS TARG -0.2720,-0.2720 POS TARG 0.4945, 0.5192 POS TARG -1.0137, 0.9890 ON HOLD SCHED 40% SAME ORIENT AS 01 BEFORE 01-Sep-2002 POS TARG 0.1479, 0.1345 POS TARG -0.1479,-0.1479 POS TARG 0.2690, 0.2824 POS TARG -0.4438, 0.4304 POS TARG 0.4304,-0.4438 POS TARG 0.7478, 0.0350 POS TARG -0.0350,-0.7478 POS TARG 0.0215, 1.2239 POS TARG -1.2239, 0.0215 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F475W F606W F555W F435W F814W F250W F330W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC104 ------------------------------------------------------------------------------------------------------------------------------------