9377( 2) - 02/15/02 15:54 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9377 Version: 2 Check-in Date: 15-Feb-2002 15:53:02 1.Proposal Title: NICMOS Imaging Polarimetry of Compact Proto-Planetary Nebula Dust Shells ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Toshiya Ueta University of Illinois at Urbana - Champaign CoI: Prof. Margaret Meixner University of Illinois at Urbana-Champaign N CoI: Dr. Koji Murakawa Subaru Telescope N ------------------------------------------------------------------------------------ 5. Abstract We propose to resolve the structure of 4 proto-planetary nebula (PPN) dust shells by means of imaging polarimetry using NICMOS. In our previous WFPC2 imaging surveys, these PPNs show a compact elliptical nebulosity (of radius 0.5 to 2") with a prominently visible central star. These PPNs appear to be members of a distinct class of PPNs, compared with bipolar nebulae in which an optically thick dust lane obscures the central star. Based on our previous mid-IR PPN survey, these PPNs are expected to host an optically thin, edge-on toroidal dust shell as evidence for the intrinsic axisymmetry of the PPN shells caused by an equatorially-enhanced mass loss during the asymptotic giant branch phase. These PPNs, however, are too compact to be fully resolved at mid-IR even with large ground-based telescopes because mid-IR images are diffraction- limited. The unique ability of imaging polarimetry at unprecedented high resolution makes HST the only instrument capable of isolating dust-scattered, polarized light from the shell and directly resolving the structure of compact PPNs without being hindered by the dominantly bright central star. These observations and following analysis with our radiative transfer code will provide crucial clues to the physical mechanism that drives the axisymmetric mass loss from originally spherically symmetric stars, which still remains to be one of the fundamental problems in astrophysics. ------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 2] Observations Description ------------------------ We will use the NICMOS Camera 1 (NIC1) in the J polarimetric filters (POL0S, POL120S, and POL240S) to perform imaging polarimetry on 4 PPNs found to show the bright central star in a faint, elliptical nebulosity in our previous WFPC2 observations. The MULTIACCUM mode will be used to maximize the dynamic range, remove cosmic rays, and repair pixels that may be saturated due to the bright central star. For each object, an on-chip, 4- or 5-point dithering pattern will be used to obtain images. At each of the dithering location, we will rotate the filer wheel to take images with all three polarization filters because the filter change overhead (< 16 sec) is smaller than the small angle maneuver overhead (< 30 sec). In this way, 12 or 15 exposures (3 filters * [4 or 5] positions) per object will be taken in one visit to an object. In our proposed observations, obtaining polarized flux intrinsic to the PPN shell around a very bright central star is crucial to capture the structure of the dust shell. Therefore, a removal of the PSF is critical to achieve our science goals. To get a satisfactory removal of the PSF and the polaroid ghosts, we will also observe a PSF standard star for PSF subtraction, using the same science exposure sequence during an orbit because the thermal stresses during an orbit move things around - like the cold stop and PAM mirrors - and significantly affect the structure of the PSF diffraction spikes. In addition, we will take DARKs after each science exposures because the bright targets will most likely saturate the detector array and we need to take DARKs to minimize effects from the image persistence known to remain after oversaturatrated exposures. Our PSF standard, HD 12088, is a G5 star (science targets are F-G type) and its brightness is about equal to the mean brightness of the science targets. So, its PSF structure is expected to be at least similar to that of our target sources. Although this source is not a polarization standard, the stellar emission is expected to be unpolarized because of the star's high proper motion (most unpolarized stars are high proper motion stars). Real Time Justification ----------------------- To get a satisfactory removal of the PSF and the polaroid ghosts with just one PSF standard, we need to minimize time variations of the PSF structure resulting from time variations of the thermal stresses on the instrument. Therefore, all observations need to be completed within a short time interval while the thermal effects on the PSF structure is expected to remain relatively constant. We selected the PSF calibration standard, HD 12088, because of the proximity of the star to IRAS 02229+6208, a science target in the CVZ. They are relatively close together (4.5 degrees separation) and can be observed in the same CVZ orbit. Calibration Justification ------------------------- A proper removal of the PSF is critical to achieve our science goals. To get a satisfactory removal of the PSF and the polaroid ghosts, we need to observe a PSF standard star using the same science exposure sequence during an orbit because the thermal stresses during an orbit move things around - like the cold stop and PAM mirrors. Additional Comments ------------------- ------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD56126 STAR, POST-AGB STAR RA=7H 16M 10.26S +/- 0.5", J2000 V = 8.14+/-0.41 DEC=9D 59' 48.0" +/- 0.5" J = 7.04+/-0.01 TYPE=F5I SURF(12500)=3.8+/-0.5e-14 Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Comments: Coordinates are from the Guide Star Catalog as well as the Hipparcos/Tycho catalogue. 2 IRASZ02229+6 STAR, POST-AGB STAR RA=2H 26M 41.77S +/- 0.2", J2000 V = 11.74+/-0.37 208 DEC=62D 21' 22.2" +/- 0.2", J = 6.66+/-0.02 PLATE-ID=01MW TYPE=G9 SURF(12500)=3.4+/-0.5e-14 Coordinate Source: GUIDE_STAR_CATALOG 3 IRAS04296+34 STAR, POST-AGB STAR RA=4H 32M 56.99S +/- 0.2", J2000 V = 13.66+/-0.41 29 DEC=34D 36' 12.5" +/- 0.2", J = 9.55+/-0.07 PLATE-ID=003V TYPE=G0IA SURF(12500)=9.6+/-0.5e-15 Coordinate Source: GUIDE_STAR_CATALOG 4 IRAS06530- STAR, POST-AGB STAR RA=6H 55M 31.81S +/- 1", DEC=-2D J2000 V = 14.11+/-0.05 0213 17' 28.55" +/- 1", PLATE-ID=00TW J = 9.66+/-0.02 TYPE=F0I SURF(12500)=3.8+/-0.5e-15 Coordinate Source: GSC_SURVEY_PLATE Comments: Coordinates are from SC survey plate, and are confirmed with previous HST image. 5 HD12088 STAR, G V-IV, RA=2H 0M 31.83S +/- 0.5", J2000 V = 9.05+/-0.05 CALIBRATION, POINT DEC=59D 39' 10.4" +/- 0.5" B-V = 0.73 SPREAD FUNCTION Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Comments: Calibration Star for PSF subtraction. Coordinates are from the Hipparcos/Tycho Catalogue. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.0089067 -0.1258 0.002 9377( 2) - 02/15/02 15:54 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 10 Primary_Pattern Secondary_Pattern Pattern_Type NIC-SPIRAL-DITH Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 4.4075 Coordinate_Frame POS-TARG Pattern_Orient 0.1397 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 5] Visit: 10 Visit Priority: Visit Requirements: SEQ 10, 20, 30, 40 WITHIN 7 D 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 IRAS04296+3 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP8 1 DEF PATTERN 10 10-15 POS TARG 429 CUM X -2.2145,-2.2145 ------------------------------------------------------------------------------------------------------------------------------------ 11 IRAS04296+3 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 429 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 12 IRAS04296+3 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 429 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 13 IRAS04296+3 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 429 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 14 IRAS04296+3 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 429 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 15 IRAS04296+3 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 429 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 20 IRAS04296+3 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP8 1 DEF 429 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 21 IRAS04296+3 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 429 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 22 IRAS04296+3 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP8 1 DEF SAME POS AS 20 429 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 23 IRAS04296+3 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 429 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 24 IRAS04296+3 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP8 1 DEF SAME POS AS 20 429 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 25 IRAS04296+3 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 429 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 6] Visit: 20 Visit Priority: Visit Requirements: CVZ 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 IRASZ02229+ NIC1 MULTIAC NIC1-FI POL0S NSAMP=15,SAMP-SEQ=STEP8 1 DEF PATTERN 10 10-15 POS TARG 6208 CUM X -2.2145,-2.2145 ------------------------------------------------------------------------------------------------------------------------------------ 11 IRASZ02229+ NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 6208 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 12 IRASZ02229+ NIC1 MULTIAC NIC1-FI POL120S NSAMP=15,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 6208 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 13 IRASZ02229+ NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 6208 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 14 IRASZ02229+ NIC1 MULTIAC NIC1-FI POL240S NSAMP=15,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 6208 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 15 IRASZ02229+ NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 6208 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 30 HD12088 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP1 1 DEF PATTERN 10 30-35 POS TARG CUM X -2.2145,-2.2145 ------------------------------------------------------------------------------------------------------------------------------------ 31 HD12088 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 X Comments: NIC1 imaging persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 32 HD12088 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP1 1 DEF POS TARG -2.2145,-2.2145 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 33 HD12088 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 X Comments: NIC1 imaging persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 34 HD12088 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP1 1 DEF POS TARG -2.2145,-2.2145 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 35 HD12088 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 X Comments: NIC1 imaging persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 40 HD12088 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP1 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 HD12088 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 40 X Comments: NIC1 imaging persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 42 HD12088 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP1 1 DEF SAME POS AS 40 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 43 HD12088 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 40 X Comments: NIC1 imaging persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 44 HD12088 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP1 1 DEF SAME POS AS 40 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 8] Visit: 30 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 IRAS06530-0 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP8 1 DEF PATTERN 10 10-15 POS TARG 213 CUM X -2.2145,-2.2145 ------------------------------------------------------------------------------------------------------------------------------------ 11 IRAS06530-0 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 213 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 12 IRAS06530-0 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 213 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 13 IRAS06530-0 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 213 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 14 IRAS06530-0 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 213 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 15 IRAS06530-0 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 213 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 20 IRAS06530-0 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP8 1 DEF 213 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 21 IRAS06530-0 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 213 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 22 IRAS06530-0 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP8 1 DEF SAME POS AS 20 213 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 23 IRAS06530-0 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 213 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 24 IRAS06530-0 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP8 1 DEF SAME POS AS 20 213 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 9] Visit: 40 Visit Priority: Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 HD56126 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP8 1 DEF PATTERN 10 10-15 POS TARG CUM X -2.2145,-2.2145 ------------------------------------------------------------------------------------------------------------------------------------ 11 HD56126 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 12 HD56126 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 13 HD56126 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 14 HD56126 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP8 1 DEF POS TARG -2.2145,-2.2145 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 15 HD56126 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S POS TARG -2.2145,-2.2145 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 20 HD56126 NIC1 MULTIAC NIC1-FI POL0S NSAMP=18,SAMP-SEQ=STEP8 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 21 HD56126 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 22 HD56126 NIC1 MULTIAC NIC1-FI POL120S NSAMP=18,SAMP-SEQ=STEP8 1 DEF SAME POS AS 20 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 23 HD56126 NIC1 ACCUM NIC1-FI BLANK NREAD=9 2 5.158 S SAME POS AS 20 X Comments: NIC1 image persistence removal exposure ------------------------------------------------------------------------------------------------------------------------------------ 24 HD56126 NIC1 MULTIAC NIC1-FI POL240S NSAMP=18,SAMP-SEQ=STEP8 1 DEF SAME POS AS 20 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 9377( 2) - 02/15/02 15:54 - [ 10] Summary Form for Proposal 9377 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=18 SAMP-SEQ=STEP8 NREAD=9 NSAMP=15 SAMP-SEQ=STEP1 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 10, 20, 30, 40 WITHIN 7 D PATTERN 10 10-15 POS TARG -2.2145,-2.2145 POS TARG -2.2145,-2.2145 SAME POS AS 20 CVZ PATTERN 10 30-35 POS TARG -2.2145,-2.2145 SAME POS AS 40 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements POL0S BLANK POL120S POL240S ------------------------------------------------------------------------------------------------------------------------------------ Target Names IRAS04296+3429 IRASZ02229+6208 HD12088 IRAS06530-0213 HD56126 ------------------------------------------------------------------------------------------------------------------------------------