7285( 9) - 06/21/99 14:33 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7285 Version: 9 Check-in Date: 08-Feb-1999 14:43:19 1.Proposal Title: Collimation of Astrophysical Jets: The Proto-Planetary Nebula He 3-1475 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: J. Harrington University of Maryland CoI: John Blondin North Carolina State University N CoI: Kazimierz Borkowski North Carolina State University N ------------------------------------------------------------------------------------ 5. Abstract Recent observations of the proto-planetary nebula He3-1475 in the N II Lambda6584 line with the HST WFPC2 have revealed what appear the be large scale flows being collimated into narrow bipolar jets. This is a unique object: we may be observing the actual collimation process of an astrophysical jet. Morphology alone, however, can be misleading. To confirm this interpretation and make direct comparisons with hydrodynamical models, it is crucial to observe the velocity field of the flow at the highest spatial resolution. We propose to do this by mapping the jets using the long-slit, medium resolution mode of STIS. We also propose supplemental observations: low resolution STIS spectra for nebular diagnostics, narrow-band imaging with WFPC2 in additional emission lines, imaging with NICMOS in the 2.12 Mum H_2 line and broad-band polarimetry with NICMOS and FOC. The polarimetry and H_2 imaging are important to determine the structure of the confining molecular torus close to the star. It is also interesting to n ote that because of its high expansion velocity, a second epoch N II Lambda6584 WFPC2 image should show measurable angular expansion after only a year. This could provide an independent distance. ------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 2] Observations Description ------------------------ To map the velocity field we will observe the strongest line, N IILambda 6585 with the G750M grating, which will give us resolution of ~50 km s^-1. We measured the flux within a circle 0.36 arcsec in radius centered on the lower converging cone in Fig. 1 and obtained 3.5 * 10^-14 ergs cm^-2 s^-1, of which about half is diffuse scattered light and half the distinct shock features of interest. Assuming a (local) velocity range of 200 km s^-1 (sim5Angstrom), we have a flux of 8 * 10^-15 ergs cm^-2 s^-1 AA^-1 arcsec^-2. The STIS estimator then yields S/N = 18 for an exposure of 40 min with the 0.1 arcsec slit. We need a high S/N because there may be important fainter components. We also want to obtain good data on the weaker HAlpha and S II lines which are in the G750M spectral range. Our most important objective is to fully map the velocity field in the ``collimation region'' -- the cones between the star and the first knots. With the 0.1 arcsec slit this will require 9 adjacen t slit positions (i.e., stepping w ith PATTERN=PERP-TO-SLIT) aligned along the jets. With overheads, one orbit will be needed for each position (one exposure will be shortened to allow acquisition and peak-up). Thus the velocity mapping will require 9 orbits. We also want to obtain low resolution spectra using G430L and G750L. These will provide little velocity information, but will provide diagnostics of the physical conditions. We propose the 0.2 arcsec slit at 4 positions to cover essentially the same region. Exposures of 10 min will provide S/N >= 3 for lines such as HBeta, O III Lambda5007, N II Lambda5755, etc. We estimate 3 orbits to obtain these (8 * 10 min) low resolution spectra. Imaging polarimetry of the U-shaped reflection nebula with FOC will take one orbit. From our F658N image of He 3-1475 we found the maximum surface brightness of the reflection nebula to be equal to 3.9 * 10^-14 ergs cm^-2 s^-1 AA^-1 arcsec^-2 at 6584 Angstrom. Based on ground-based spectra, the maximum surface brightness at 5500 Angstrom is about two-thirds of this value. We then expect at most 0.1 counts s^-1 per FOC pixel in the 512 * 512 format with F550M filter and any of the polarizers. This is safely in the linear regime for extended sources. At the top of the U-shaped reflection nebula, the surface brightness is one order of magnitude lower. In about 600 sec exposures with each of the three polarizers, we will be able to obtain good (S/N>5 within 0.05x0.05 arcsec^2 area) images of the reflection nebula around the jet collimation region. As explained above, we want to obtain a second epoch N IILambda 6585 image with WFPC2 through the F658N filter to look for angular expansion. This image should be deeper than the 10 min snapshot exposure (Fig. 1) since this is the line which will be used for the velocity mapping. We propose a 25 min exposure in this line. The WFPC2 exposure times of the other lines can only be estimated from the ground based fluxes seen in the knots^6. We can obtain a S/N in HAlpha a bit worse than in Fi g. 1 in 15 min. The other lines ar e rather weaker; 20 min exposures will give counts 60 those seen in the N II image for F673N, F631N, F502N, and F487N, respectively. The weakest, HBeta, will still be important to combine with PAlpha for the reddening map. We thus need 3 orbits for the WFPC2 imaging. To estimate the NICMOS exposure times for polarization, we note that the continuum is basically flat as far as ground - based spectra extend^6 (~10, 000 Angstrom). The sensitivity of NICMOS then assures that we will have high S/N in exposures of 5 min. The observations of the H I PAlpha line can estimated based on the theoretical PAlpha/HAlpha ratio of 0.12 and the earlier estimates of the HAlpha for the WFPC2 imaging. We conclude that even without the advantage of differential reddening, fluxes in the jet will be ~ 1.5 * 10^-14 ergs cm^-2 s^-1 arcsec^-2. A 5 min exposure with NICMOS F187N will give a S/N >5. With the adjacent continuum filter F190N and off source exposures, we have a total time of 20 min. There is no sure way to estimate the lik ely flux in the H_2 2.12 Mum line; we feel that once again 5 min is appropriate. The time required for the NICMOS observations will then be 2 orbits, with the polarization taking only part of the first orbit and line obserations using the remainder and another whole orbit. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 3] Data Distribution Paper Products: Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HE3-1475 ISM, PLANETARY NEBULA RA=17H 45M 14.13S +/- 0.1", DEC= J2000 V = 14.5+/-0.5 -17D 56' 46.6" +/- 0.1", PLATE- E(B-V) = 0.7+/-0.2 ID = 060B TYPE=BE SURF-LINE(6585)=8+/-2e-14 W-LINE(6585)=5+/-1 Comments: The magnitude of 14.5 refers to the stellar core, which is seen against/through a scattering nebula. The total magnitude of star+nebula is V = 12.9. The science observations are of the surrounding nebulosity. SURF-CONT(5500)=2.6+/-0.2E-14 SURF- LINE(18750)=1.5+/-0.5E-14 SURF-CONT(10000)=5+/-1E-14 SURF-LINE(6563)=5+/-2E-14 SURF-LINE(5007)=3+/-1E-15 SURF-LINE(6300)=1.8+/-0.5E-14 SURF-LINE(4861)=1.5+/- 0.5E-15 SURF-LINE(6730)=2.4+/-0.5E-14 2 HE3-1475-2 ISM, PLANETARY NEBULA RA=17H 45M 14.195S +/- 0.3", J2000 V = 14.5+/-0.5 DEC=-17D 56' 46.9" +/- 0.3", E(B-V) = 0.7+/-0.2 PLATE-ID=060B TYPE=BE SURF-LINE(6585)=8+/-2e-14 W-LINE(6585)=5+/-1 Comments: Same as target 1 with slightly updated coordinates. 7285( 9) - 06/21/99 14:33 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 180D TO 180D SCHED 100% 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 HE3-1475-2 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.3 S ONBOARD ACQ FOR 30 CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 HE3-1475-2 STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2,PATTERN=PERP-TO-SLIT, 1 21.0 M POS TARG -0.4, 0.0 CD NUM-POS=9,STEP-SIZE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 6] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENT AS 01 SCHED 100% 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 ------------------------------------------------------------------------------------------------------------------------------------ 35 HE3-1475-2 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.3 S ONBOARD ACQ FOR 50 CD P ------------------------------------------------------------------------------------------------------------------------------------ 50 HE3-1475-2 STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2,PATTERN=PERP-TO-SLIT, 1 16.0 M POS TARG -0.4, 0.0 CD NUM-POS=9,STEP-SIZE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 7] Visit: 03 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 HE3-1475 NIC2 MULTIAC NIC2 F212N PATTERN=SPIRAL-DITH-CHOP, 1 DEF CUM CHOP-SIZE=60.0,SAMP-SEQ=STEP16, NSAMP=20,NUM-POS=4,DITH-SIZE=2.0 ------------------------------------------------------------------------------------------------------------------------------------ 20 HE3-1475 NIC2 MULTIAC NIC2 F215N PATTERN=SPIRAL-DITH-CHOP, 1 DEF CUM CHOP-SIZE=60.0,SAMP-SEQ=STEP16, NSAMP=20,NUM-POS=4,DITH-SIZE=2.0 ------------------------------------------------------------------------------------------------------------------------------------ 30 HE3-1475 NIC2 MULTIAC NIC2 F187N SAMP-SEQ=STEP16,NSAMP=20, 1 DEF CUM PATTERN=SPIRAL-DITH,NUM-POS=2, DITH-SIZE=2.0 ------------------------------------------------------------------------------------------------------------------------------------ 40 HE3-1475 NIC2 MULTIAC NIC2 F190N SAMP-SEQ=STEP16,NSAMP=19, 1 DEF CUM PATTERN=SPIRAL-DITH,NUM-POS=2, DITH-SIZE=2.0 ------------------------------------------------------------------------------------------------------------------------------------ 50 HE3-1475 NIC1 MULTIAC NIC1 POL0S NSAMP=20,SAMP-SEQ=STEP8, 1 DEF CUM PATTERN=SPIRAL-DITH,NUM-POS=2, DITH-SIZE=1.0 ------------------------------------------------------------------------------------------------------------------------------------ 60 HE3-1475 NIC1 MULTIAC NIC1 POL120S SAMP-SEQ=STEP8,NSAMP=20, 1 DEF CUM PATTERN=SPIRAL-DITH,NUM-POS=2, DITH-SIZE=1.0 ------------------------------------------------------------------------------------------------------------------------------------ 70 HE3-1475 NIC1 MULTIAC NIC1 POL240S SAMP-SEQ=STEP8,NSAMP=20, 1 DEF CUM PATTERN=SPIRAL-DITH,NUM-POS=2, DITH-SIZE=1.0 ------------------------------------------------------------------------------------------------------------------------------------ 80 HE3-1475 NIC1 MULTIAC NIC1 F110W SAMP-SEQ=STEP8,NSAMP=15, 1 DEF CUM PATTERN=SPIRAL-DITH,NUM-POS=2, DITH-SIZE=1.0 ------------------------------------------------------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 8] Visit: 04 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 HE3-1475 FOC/96 IMAGE 512X512 F550M, 1 11 M POL0 ------------------------------------------------------------------------------------------------------------------------------------ 20 HE3-1475 FOC/96 IMAGE 512X512 F550M, 1 11 M POL60 ------------------------------------------------------------------------------------------------------------------------------------ 30 HE3-1475 FOC/96 IMAGE 512X512 F550M, 1 11 M POL120 ------------------------------------------------------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 9] Visit: 05 Visit Priority: Visit Requirements: SAME ORIENT AS 01 SCHED 100% 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 ------------------------------------------------------------------------------------------------------------------------------------ 20 HE3-1475-2 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.3 S ONBOARD ACQ FOR 60, 70 CD P ------------------------------------------------------------------------------------------------------------------------------------ 60 HE3-1475-2 STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2,PATTERN=PERP-TO-SLIT, 1 720.0 S POS TARG -0.4, 0.0 CD NUM-POS=4,STEP-SIZE=0.2 ------------------------------------------------------------------------------------------------------------------------------------ 70 HE3-1475-2 STIS/C ACCUM 52X0.2 G750L 7751 CR-SPLIT=2,PATTERN=PERP-TO-SLIT, 1 720.0 S POS TARG -0.4, 0.0 CD NUM-POS=4,STEP-SIZE=0.2 ------------------------------------------------------------------------------------------------------------------------------------ 75 CCDFLAT STIS/C ACCUM 52X0.2 G750L 7751 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 10] Visit: 06 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 HE3-1475-2 WFPC2 IMAGE PC1-FIX F658N DITHER-TYPE=LINE,CR-SPLIT=0.5 1 600.0 S ------------------------------------------------------------------------------------------------------------------------------------ 20 HE3-1475-2 WFPC2 IMAGE PC1-FIX F656N 1 800 S ------------------------------------------------------------------------------------------------------------------------------------ 25 HE3-1475-2 WFPC2 IMAGE PC1-FIX F656N 1 30 S ------------------------------------------------------------------------------------------------------------------------------------ 30 HE3-1475-2 WFPC2 IMAGE PC1-FIX F502N 1 800.0 S ------------------------------------------------------------------------------------------------------------------------------------ 40 HE3-1475-2 WFPC2 IMAGE PC1-FIX F631N CR-TOLERANCE=0.3 1 800.0 S ------------------------------------------------------------------------------------------------------------------------------------ 50 HE3-1475-2 WFPC2 IMAGE PC1-FIX F487N 1 800.0 S ------------------------------------------------------------------------------------------------------------------------------------ 60 HE3-1475-2 WFPC2 IMAGE PC1-FIX F673N 1 800.0 S ------------------------------------------------------------------------------------------------------------------------------------ 7285( 9) - 06/21/99 14:33 - [ 11] Summary Form for Proposal 7285 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.1 NIC2 NIC1 512X512 52X0.2 PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD NIC2 NIC1 FOC/96 WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM MULTIACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT STEP-SIZE=0.1 NUM-POS=9 DITH-SIZE=2.0 NUM-POS=4 NUM-POS=2 PATTERN=SPIRAL-DITH DITH-SIZE=1.0 NSAMP=20 SAMP-SEQ=STEP8 NSAMP=15 STEP-SIZE=0.2 PATTERN=PERP-TO-SLIT CR-SPLIT=0.5 CR-TOLERANCE=0.3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 180D TO 180D SCHED 100% ONBOARD ACQ FOR 30 POS TARG -0.4, 0.0 SAME ORIENT AS 01 SCHED 100% ONBOARD ACQ FOR 50 ONBOARD ACQ FOR 60, 70 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G750M F212N F215N F187N F190N POL0S POL120S POL240S F110W F550M,POL0 F550M,POL60 F550M,POL120 G430L G750L F658N F656N F502N F631N F487N F673N ------------------------------------------------------------------------------------------------------------------------------------ Target Names HE3-1475-2 HE3-1475 CCDFLAT ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 6581 4300 7751 ------------------------------------------------------------------------------------------------------------------------------------