7843( 3) - 12/01/97 08:48 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7843 Version: 3 Check-in Date: 01-Dec-1997 08:46:21 1.Proposal Title: Testing Protostellar Collapse Theory through Extinction Mapping ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: DAVID WILNER CENTER FOR ASTROPHYSICS CoI: Hua Chen University of Arizona N CoI: Phil Myers Smithsonian Astrophysical Observatory N ------------------------------------------------------------------------------------ 5. Abstract The identification of collapsing protostars remains a ``holy grail'' of star formation studies. The best collapse candidate is generally recognized to be B335, an isolated round globule containing a deeply embedded low luminosity young stellar object (detected only at Lambda>60 Mum). In an influential study, Zhou et al. (1993) observed a variety of trace molecules in B335 and showed that detailed radiative transfer models based on the velocity and density fields of the ``inside-out'' collapse theory developed by Shu (1977) reproduced the spectra extremely well. Here we propose to use NICMOS to obtain near-infrared photometry of background stars shining through B335, to measure the density field in a way that suffers from none of the problems inherent in molecular line work (abundances, opacities, unknown collision rates, etc.). Ground based data show that the projected reddening distribution at large radii (>30'') is in good agreement with an n\propto r^-2 density profile. Deeper observations using NICMOS will probe into higher extinctions and smaller radii and show directly if the density field has relaxed to the n\propto r^-1.5 form predicted for collapse. The proposed observations take advantage of the high sensitivity of NICMOS to sample the B335 infall zone to equivalent visual extinctions of 50 magnitudes or more, a regime that simply cannot be probed from the ground. ------------------------------------------------------------------------------------ 7843( 3) - 12/01/97 08:48 - [ 2] Observations Description ------------------------ Updated on 11/20/97 by HC Added NIC2 parallels for orbit 1, and NIC1 & NIC2 parallels to orbits 2-7. Although the parallels will have little use, they will help to reduce the readout interference pattern. Note that There is no NIC1 parallel to the first orbit since adding it would introduce data dumps. The NIC3 observations of B335 will be made in two parts: (1) imaging a radial strip through F160W and F222M in 1 orbit, and (2) imaging a field centered on the mm peak through F160W and F222M in 6 orbits. For the first part, we will image five adjacent fields defined by POS TARG at (0,24), (0,72), (0,120), (0,168), and (0, 216). At each position, we obtain two images in ONE-CHOP mode with 3.1" offset. This results in a 243'' long strip with the millimeter peak 1.6'' from the edge. With an exposure of 56s per point per filter, the 10sigma per pixel limiting magnitudes are H=22.0 and K=18.9. Since it is important for us to obtain fields 2-4' away from the center, we accept the overhead of GS re- acquisition during the first orbit. For the second part, we will map the central region of B335 in a SPIRAL-DITH pattern with 9 positions. The center position is the millimeter continuum peak. The dither is 10.1" for half pixel sampling. This results in a 71.4"x71.4" map. With an exposure of 896s per point per filter, the 10sigma per pixel limiting magnitudes for the central 30" are H=26.4 and K=22.5. We do not specify an ORIENT in order to maximize the visibility windows, We will use dithering frames to construct a median background and do not need separate background measurements. This project would benefit from the planned NIC3 campaign but does not require it. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: DAT Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7843( 3) - 12/01/97 08:48 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 B335 STAR,STAR FORMING RA=19H 37M 0.89S +/- 0S,DEC=7D J2000 H = 10+/-0.5 REGION 34' 10.0" +/- 0" 7843( 3) - 12/01/97 08:48 - [ 4] Visit: 01 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 B335 NIC3 MULTIAC NIC3-FI F160W 1.60 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,24.0 PAR 12 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 10 ------------------------------------------------------------------------------------------------------------------------------------ 12 ANY NIC2 MULTIAC NIC2-FI F160W 1.60 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 20 B335 NIC3 MULTIAC NIC3-FI F222M 2.2 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,24.0 PAR 22 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 20 ------------------------------------------------------------------------------------------------------------------------------------ 22 ANY NIC2 MULTIAC NIC2-FI F222M 2.20 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 30 B335 NIC3 MULTIAC NIC3-FI F160W 1.60 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,72.0 PAR 32 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 30 ------------------------------------------------------------------------------------------------------------------------------------ 32 ANY NIC2 MULTIAC NIC2-FI F160W 1.60 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 40 B335 NIC3 MULTIAC NIC3-FI F222M 2.2 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,72.0 PAR 42 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 40 ------------------------------------------------------------------------------------------------------------------------------------ 42 ANY NIC2 MULTIAC NIC2-FI F222M 2.20 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 50 B335 NIC3 MULTIAC NIC3-FI F160W 1.60 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,120.0 PAR 52 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 50 ------------------------------------------------------------------------------------------------------------------------------------ 52 ANY NIC2 MULTIAC NIC2-FI F160W 1.60 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 60 B335 NIC3 MULTIAC NIC3-FI F222M 2.2 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,120.0 PAR 62 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 60 ------------------------------------------------------------------------------------------------------------------------------------ 62 ANY NIC2 MULTIAC NIC2-FI F222M 2.20 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 70 B335 NIC3 MULTIAC NIC3-FI F160W 1.60 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,168.0 PAR 72 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 70 ------------------------------------------------------------------------------------------------------------------------------------ 72 ANY NIC2 MULTIAC NIC2-FI F160W 1.60 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 80 B335 NIC3 MULTIAC NIC3-FI F222M 2.2 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,168.0 PAR 82 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 80 ------------------------------------------------------------------------------------------------------------------------------------ 7843( 3) - 12/01/97 08:48 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 82 ANY NIC2 MULTIAC NIC2-FI F222M 2.20 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 90 B335 NIC3 MULTIAC NIC3-FI F160W 1.60 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,216.0 PAR 92 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 90 ------------------------------------------------------------------------------------------------------------------------------------ 92 ANY NIC2 MULTIAC NIC2-FI F160W 1.60 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 100 B335 NIC3 MULTIAC NIC3-FI F222M 2.2 PATTERN=ONE-CHOP,CHOP-SIZE=3.1, 1 DEF POS TARG 0,216.0 PAR 102 CUM X NUM-POS=2,SAMP-SEQ=STEP8,NSAMP=12 WITH 100 ------------------------------------------------------------------------------------------------------------------------------------ 102 ANY NIC2 MULTIAC NIC2-FI F222M 2.22 SAMP-SEQ=STEP8,NSAMP=12 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 200 B335 NIC3 MULTIAC NIC3-FI F160W 1.60 PATTERN=SPIRAL-DITH, 1 DEF PAR 201-202 WITH 200 CUM X DITH-SIZE=10.1,NUM-POS=9, SAMP-SEQ=STEP128,NSAMP=16 ------------------------------------------------------------------------------------------------------------------------------------ 201 ANY NIC1 MULTIAC NIC1-FI F160W 1.60 SAMP-SEQ=STEP128,NSAMP=16 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 202 ANY NIC2 MULTIAC NIC2-FI F160W 1.60 SAMP-SEQ=STEP128,NSAMP=16 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 210 B335 NIC3 MULTIAC NIC3-FI F222M 2.22 PATTERN=SPIRAL-DITH, 1 DEF PAR 211-212 WITH 210 CUM X DITH-SIZE=10.1,NUM-POS=9, SAMP-SEQ=STEP128,NSAMP=16 ------------------------------------------------------------------------------------------------------------------------------------ 211 ANY NIC1 MULTIAC NIC1-FI F110W 1.10 SAMP-SEQ=STEP128,NSAMP=16 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 212 ANY NIC2 MULTIAC NIC2-FI F222M 2.20 SAMP-SEQ=STEP128,NSAMP=16 1 DEF CUM X ------------------------------------------------------------------------------------------------------------------------------------ 7843( 3) - 12/01/97 08:48 - [ 6] Summary Form for Proposal 7843 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC3 NIC2 NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PATTERN=ONE-CHOP CHOP-SIZE=3.1 NUM-POS=2 SAMP-SEQ=STEP8 NSAMP=12 NSAMP=16 SAMP-SEQ=STEP128 NUM-POS=9 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0,24.0 PAR 12 WITH 10 POS TARG 0,24.0 PAR 22 WITH 20 POS TARG 0,72.0 PAR 32 WITH 30 POS TARG 0,72.0 PAR 42 WITH 40 POS TARG 0,120.0 PAR 52 WITH 50 POS TARG 0,120.0 PAR 62 WITH 60 POS TARG 0,168.0 PAR 72 WITH 70 POS TARG 0,168.0 PAR 82 WITH 80 POS TARG 0,216.0 PAR 92 WITH 90 POS TARG 0,216.0 PAR 102 WITH 100 PAR 201-202 WITH 200 PAR 211-212 WITH 210 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W F222M F110W ------------------------------------------------------------------------------------------------------------------------------------ Target Names B335 ANY ------------------------------------------------------------------------------------------------------------------------------------