7839( 3) - 12/08/97 13:46 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7839 Version: 3 Check-in Date: 08-Dec-1997 13:44:53 1.Proposal Title: Colliding Stellar Winds: Near-IR Imaging of the Protoplanetary Nebula M1--92 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Valentin Bujarrabal OBSERVATORIO ASTRONOMICO NACIONAL CoI: Raghvendra Sahai Jet Propulsion Laboratory/ Caltech N CoI: Javier Alcolea Observatorio Astronomico Nacional Y CoI: Carmen Sanchez Contreras Observatorio Astronomico Nacional N ------------------------------------------------------------------------------------ 5. Abstract The interaction between a fast post-AGB bipolar outflow and a slowly expanding, dense AGB envelope is believed to be the dominant dynamical effect in the evolution of protoplanetary nebulae (PPNe) and the shaping of planetary nebulae. We are carrying out a multi-wavelength study of the PPN M1--92, to probe each of the important components in the interaction process. Millimeter-wave CO interferometry has revealed that the shock-accelerated, low-energy material is distributed in the thin walls of a double cavity covering the whole nebula, and our WFPC2 optical emission-line images show the presence of highly excited countershocks propagating in a very collimated post-AGB jet within the CO double cavity. We propose complementary NICMOS narrow-band (F212N, F215N), broad -band (F165M, F222M) and polarimetric (2 Mum POL filters) imaging observations of M1--92 in order (a) to study the intermediate-excitation gas at the interface between the cold molecular and hot atomic gas (identified from our ground-based observations of H_2 vibrational line emission) and perhaps also at the leading bow-shock; (b) to study the concentration of dust around the central star in M1--92, in a 2 arcsec wide region, that may play an important role in the collimation of the fast jets; and (c) to search for a low-luminosity companion which is hypothesized to initiate bipolar symmetry in PPNe. ------------------------------------------------------------------------------------ 7839( 3) - 12/08/97 13:46 - [ 2] Observations Description ------------------------ We propose to image the protoplanetary nebula M1--92 using NICMOS (NIC2 camera). The spectral filters F212N, F215N, F165M and F222M (F222M selected instead of F205W for minimizing contamination by H_2 2.1Mum line) and the polarizers POL0L, POL120L and POL240L are required. In the interesting regions of M1--92, the peak 2-Mu continuum is as high as ~ 10^-14 Watts m^-2 arcsec^-2 mu^-1, with extended low surface brightness regions which are significantly fainter. Assuming that the flux is smoothly distributed in regions much larger than the NICMOS pixel size, we estimate a signal/noise ratio (SNR)=3 in each of the F212N and F215N filters in 1 sec exposures for the regions of peak intensity. Since the line is about 1/3 of the total in F212N, and a SNR of about 30-40 is needed at the peak to properly map the line in the low surface- brightness extended regions, exposures of about 25 minutes are needed per filter. In the wide filters (F165M & F222M), only a few minutes are necessary to get a good S/N ratio. The spatially-averaged percentage polarization in the M1--92 lobes is a few percentage. polarization filter in order to obtain a sensitivity of a few percentage polarization, which led to the detection of a low-luminosity companion (whose signature was a compact region of little or no polarization within an extended region of high polarization). We will require similar exposure times for M1--92 which has a comparable surface brightness in the equatorial dense disk region. Since only low-resolution observations exist, we cannot rule out that the flux is concentrated in very compact knots with much higher brightness than expected. To prevent saturation in this case, we will observe in MULTIACCUM mode (logarithmicly spaced exposures). Dithering will be requested to eliminate instrumental effects, but background measurements are not necessary in view of the high intensity of the source (based on our experience with NIC2 observations of CRL2688 -- Sahai et al. 1997). The requested exposure times amount to about 1/2 orbit for each of F212N and F215N, about 1/4 orbit for each F160W and F205M, and about 1 1/2 orbit for polarimetry. Including overheads (filter changes/target acquisition), we request a total of 3 orbits. Real Time Justification ----------------------- ISO telescope observations of atomic FIR lines have been performed in M1--92 (and similar objects) and are currently been analyzed. FIR emission from atoms like OI, CII, SII, and SiII indicate that about 10 probably arising from the intermediate-excitation shocked gas we propose to observe with the HST. (Unfortunately, our ISO spectroscopy does not include any spatial information.) We are currently observing protoplanetary nebulae in molecular lines, mainly in ^12CO, but also in other species like ^13CO and HCN. Our data are particularly spectacular in the case of M1--92. We have also obtained high-resolution VLA observations in this source of radio continuum due to free- free emission coming from the bipolar lobes. Ionization is very probably due to shock excitation, implying shock velocities larger than 100 kms, compatible with those deduced for the region emitting in atomic lines. These data will offer a unique tool to study the total mass in the most excited component and, therefore, in the post-AGB jet (a datum that to date has been elusive). Maps of the dust continuum emission have been performed in M1--92 with ISO (ISOCAM imaging in the mid infrared) and with the Plateau de Bure interferometer (3mm and 1mm continuum with resolution of about 1"). Both observations would be used to reconstruct (complementarily to the observations requested here) the dust distribution in these sources. Dust emission at mm wavelengths indicates the presence of cool dust (< 100 K) with a mass (after conversion to total gas + dust mass) consistent with that deduced from CO data. The analysis of the ISOCAM multifrequency imaging is still in progress, it is expected to yield information on both warm dust emission (inner nebula) and scattering by cold dust (outer nebula). Previous HST/WFPC2 observations of M1--92 have been obtained in proposal 6533, mentioned below. As we mention in the text and in Related HST Programs (see below) we are also studying with similar procedures other related objects, like CRL2688, OH231.8+4.2 (of which high-resolution molecular line observations are being carried out), Roberts 22, Hen 401 etc. Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ 7839( 3) - 12/08/97 13:46 - [ 3] Data Distribution Media: DAT Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7839( 3) - 12/08/97 13:46 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M1-92 STAR,POST-AGB STAR,A0- RA=19H 36M 19.05S +/- J2000 V = 14.8 SURF(K) = 10.0+/-1.0 A3 III-I,ISM,BIPOLAR 0.05S,DEC=29D 32' 52.2" +/- OUTFLOW,SHOCK 0.1",PLATE-ID=000J FRONT,PLANETARY 7839( 3) - 12/08/97 13:46 - [ 5] 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 M1-92 NIC2 MULTIAC NIC2-FI F212N PATTERN=XSTRIP-DITH-CHOP, 1 DEF PAR 11-12 WITH 10 CUM X NUM-POS=6,OFFSET=SAM,CHOP-SIZE=28 ,DITH-SIZE=3,PATTERN-ORIENT=311, SAMP-SEQ=SPARS64,NSAMP=7 ------------------------------------------------------------------------------------------------------------------------------------ 11 ANY NIC1 ACCUM NIC1-FI F166N 1 320 S X ------------------------------------------------------------------------------------------------------------------------------------ 12 ANY NIC3 ACCUM NIC3-FI F212N 1 320 S X ------------------------------------------------------------------------------------------------------------------------------------ 20 M1-92 NIC2 MULTIAC NIC2-FI F165M SAMP-SEQ=STEP32,NSAMP=8, 1 DEF PAR 21-22 WITH 20 CUM X PATTERN=XSTRIP-DITH,NUM-POS=3, OFFSET=SAM,DITH-SIZE=3, PATTERN-ORIENT=311 ------------------------------------------------------------------------------------------------------------------------------------ 21 ANY NIC1 ACCUM NIC1-FI F166N 1 32 S X ------------------------------------------------------------------------------------------------------------------------------------ 22 ANY NIC3 ACCUM NIC3-FI F212N 1 32 S X ------------------------------------------------------------------------------------------------------------------------------------ 30 M1-92 NIC2 MULTIAC NIC2-FI F215N SAMP-SEQ=SPARS64,NSAMP=7, 1 DEF PAR 31-32 WITH 30 CUM X PATTERN=XSTRIP-DITH-CHOP, NUM-POS=6,OFFSET=SAM,CHOP-SIZE=28 ,DITH-SIZE=3,PATTERN-ORIENT=311 ------------------------------------------------------------------------------------------------------------------------------------ 31 ANY NIC1 ACCUM NIC1-FI F166N 1 320 S X ------------------------------------------------------------------------------------------------------------------------------------ 32 ANY NIC3 ACCUM NIC3-FI F212N 1 320 S X ------------------------------------------------------------------------------------------------------------------------------------ 40 M1-92 NIC2 MULTIAC NIC2-FI F222M SAMP-SEQ=STEP32,NSAMP=8, 1 DEF PAR 41-42 WITH 40 CUM X PATTERN=XSTRIP-DITH-CHOP, NUM-POS=6,OFFSET=SAM,DITH-SIZE=3, PATTERN-ORIENT=311,CHOP-SIZE=28 ------------------------------------------------------------------------------------------------------------------------------------ 41 ANY NIC1 ACCUM NIC1-FI F166N 1 32 S X ------------------------------------------------------------------------------------------------------------------------------------ 42 ANY NIC3 ACCUM NIC3-FI F212N 1 32 S X ------------------------------------------------------------------------------------------------------------------------------------ 7839( 3) - 12/08/97 13:46 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 50 M1-92 NIC2 MULTIAC NIC2-FI POL0L SAMP-SEQ=STEP128,NSAMP=11, 1 DEF PAR 51-52 WITH 50 CUM X PATTERN=XSTRIP-DITH,NUM-POS=3, OFFSET=SAM,DITH-SIZE=3, PATTERN-ORIENT=311 ------------------------------------------------------------------------------------------------------------------------------------ 51 ANY NIC1 ACCUM NIC1-FI F166N 1 256 S X ------------------------------------------------------------------------------------------------------------------------------------ 52 ANY NIC3 ACCUM NIC3-FI F212N 1 256 S X ------------------------------------------------------------------------------------------------------------------------------------ 60 M1-92 NIC2 MULTIAC NIC2-FI POL120L SAMP-SEQ=STEP128,NSAMP=11, 1 DEF PAR 61-62 WITH 60 CUM X PATTERN=XSTRIP-DITH,NUM-POS=3, OFFSET=SAM,DITH-SIZE=3, PATTERN-ORIENT=311 ------------------------------------------------------------------------------------------------------------------------------------ 61 ANY NIC1 ACCUM NIC1-FI F166N 1 256 S X ------------------------------------------------------------------------------------------------------------------------------------ 62 ANY NIC3 ACCUM NIC3-FI F212N 1 256 S X ------------------------------------------------------------------------------------------------------------------------------------ 70 M1-92 NIC2 MULTIAC NIC2-FI POL240L SAMP-SEQ=STEP128,NSAMP=11, 1 DEF PAR 71-72 WITH 70 CUM X PATTERN=XSTRIP-DITH,NUM-POS=3, OFFSET=SAM,DITH-SIZE=3, PATTERN-ORIENT=311 ------------------------------------------------------------------------------------------------------------------------------------ 71 ANY NIC1 ACCUM NIC1-FI F166N 1 256 S X ------------------------------------------------------------------------------------------------------------------------------------ 72 ANY NIC3 ACCUM NIC3-FI F212N 1 256 S X ------------------------------------------------------------------------------------------------------------------------------------ 7839( 3) - 12/08/97 13:46 - [ 7] Summary Form for Proposal 7839 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC2 NIC1 NIC3 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PATTERN=XSTRIP-DITH-CHOP NUM-POS=6 OFFSET=SAM CHOP-SIZE=28 DITH-SIZE=3 PATTERN-ORIENT=311 SAMP-SEQ=SPARS64 NSAMP=7 NUM-POS=3 NSAMP=8 PATTERN=XSTRIP-DITH NSAMP=11 SAMP-SEQ=STEP128 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PAR 11-12 WITH 10 PAR 21-22 WITH 20 PAR 31-32 WITH 30 PAR 41-42 WITH 40 PAR 51-52 WITH 50 PAR 61-62 WITH 60 PAR 71-72 WITH 70 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F212N F166N F165M F215N F222M POL0L POL120L POL240L ------------------------------------------------------------------------------------------------------------------------------------ Target Names M1-92 ANY ------------------------------------------------------------------------------------------------------------------------------------