9787( 4) - 07/09/03 06:35 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9787 Version: 4 Check-in Date: 09-Jul-2003 06:34:30 1.Proposal Title: ACS Monitoring of the Polarization of the Crab Nebula ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 12 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Dr. Jeff J. Hester Arizona State University CoI: Dr. Paul Scowen Arizona State University N CoI: Mr. Joseph Foy Arizona State University N ------------------------------------------------------------------------------------ 5. Abstract We propose to use the ACS to follow the changing polarization of relativistically moving wisps in the Crab Nebula. Making use of the known geometry of the wisps, these observations will allow us to fully characterize the radiation field from the wisps as a function of direction relative to the axis of the wisp. These observations will provide detailed information on such hard-to-measure properties as the pitch-angle distribution of the radiating particles, and will help to constrain models of the flow. More generally, these observations will add to the already rich observational legacy of HST on what is arguably the most important single object in astrophysics. ------------------------------------------------------------------------------------ Observations Description ------------------------ Observe a single pointing in the Crab with F606W crossed with each of the polarizers. Observe the same pointing wiht F550M. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9787( 4) - 07/09/03 06:35 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CRAB-POL ISM, SNR (SUPERNOVA RA=05H34M32.11S +/- 0.1", J2000 V = 15.0 REMNANT) DEC=+22D01'6.8" +/- 0.1" Coordinate Source: HST_IMAGE Comments: This is a pointing to the northeast of the Crab pulsar. The intention is to get a large fraction of the active part of the torus within the circular field of view of the polarizers used with the wide field camera in ACS. 9787( 4) - 07/09/03 06:35 - [ 3] Visit: 10 Visit Priority: Visit Requirements: PCS MODE FINE SCHED 30% On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CRAB-POL ACS/WF ACCUM WFC1-2K F550M CR-SPLIT=2,GAIN=1,COMPRESSION=DEF 1 2200 S C ------------------------------------------------------------------------------------------------------------------------------------ 2 CRAB-POL ACS/WF ACCUM WFC F606W, CR-SPLIT=2,GAIN=1,COMPRESSION=DEF 1 2400 S C POL0V ------------------------------------------------------------------------------------------------------------------------------------ 3 CRAB-POL ACS/WF ACCUM WFC F606W, CR-SPLIT=2,GAIN=1,COMPRESSION=DEF 1 2400 S C POL60V ------------------------------------------------------------------------------------------------------------------------------------ 4 CRAB-POL ACS/WF ACCUM WFC F606W, CR-SPLIT=2,GAIN=1,COMPRESSION=DEF 1 2400 S C POL120V ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 10 1 none none none 1 1 tbd 10 1 none none none 2 1 tbd 10 2 none none none 1 2 tbd 10 2 none none none 2 2 tbd 10 3 none none none 1 3 tbd 10 3 none none none 2 3 tbd 10 4 none none none 1 4 tbd 10 4 none none none 2 4 tbd 9787( 4) - 07/09/03 06:35 - [ 4] Summary Form for Proposal 9787 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC1-2K WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 GAIN=1 COMPRESSION=DEF ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE SCHED 30% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F550M F606W,POL0V F606W,POL60V F606W,POL120V ------------------------------------------------------------------------------------------------------------------------------------ Target Names CRAB-POL ------------------------------------------------------------------------------------------------------------------------------------