7323( 6) - 12/31/97 14:34 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7323 Version: 6 Check-in Date: 31-Dec-1997 14:03:39 1.Proposal Title: The TRUE three-dimensional structure of the Eta Carinae nebula ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: NINO PANAGIA SPACE TELESCOPE SCIENCE INSTITUTE CoI: Mark Clampin Space Telescope Science Institute N CoI: Antonella Nota Space Telescope Science Institute N CoI: Anna Pasquali Space telescope Science Institute N CoI: Regina Schulte-Ladbeck University of Pittsburgh N ------------------------------------------------------------------------------------ 5. Abstract We propose to use NICMOS and WFPC2 to trace independently the spatial distribution of the dust, of the ionized gas and of the neutral material in Eta Carinae nebula. The radiation we receive from the Homunculus is due to reflection of light from the central star and intrinsic emission from the ionized gas. , Only combining optical and IR imaging in selected lines, and the diffraction limited imaging offered by HST, it will be possible, for the first time, to disentangle geometry and optical depth effects. It is important to note that very important results can be achieved immediately from the direct inspection of the proposed images. For example, since the dust obscuration at BGamma is rather small and scattered light is quite negligible, the NICMOS image will provide a direct view of the projected distribution of the gas. As a subsequent step, we will model dust absorption and scattering, by applying the method outlined by Natta and Panagia (1984) to which we have added the foreground and internal absorption by dust and the effects of scattering of nebular and stellar radiation. This analysis will produce a true 3- dimensional map of the gas and dust distribution in the Eta Carinae nebula. This result will gain us fundamental insight in the nebular formation process and will further constrain the interacting wind models which are using this unique nebula as their benchmark. ------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 2] Observations Description ------------------------ As illustrated in the scientific justification, the four lines best suited for our investigation are HBeta (4861Angstrom), HAlpha (6563Angstrom), PAlpha (1.875 Mum), and BGamma (2.165 Mum), whose intensities are in ratios of 2.87:1:0.352:0.178. Since one needs to subtract the continuous emission from the total signal measured with the narrow band filters, one needs at least two more filters, the WFPC2 F547M filter and the NICMOS F200N filter, which are half-way between HBeta and HAlpha, and PAlpha and BGamma, respectively. Although more bands would be desirable for a perfect characterization of the underlying continuum for all of the lines, interpolations with the aid of ground based spectroscopy and some theoretical modelling will allow us to estimate the appropriate corrections rather accurately. In addition, polarization measurements will allow us to quantify the amount of scattered light. To achieve our scientific goals we will obtain images of Eta Carinae using WFPC2 and NICMOS. Eta Carinae is a CVZ object and so the full HST orbit is available for these observations. The WFPC2 observations will be taken in the filters F656N, F487N and F547M. While previous observations of Eta Carinae taken with these filters already exist, we believe it is important to obtain these observations at the same epoch. It should be noted that some of the highest velocity components in the outer regions nebula are redshifted out of the filter's bandpass. In this proposal we are primarily interested in the Homunculus which exhibits velocities up to 600 kms. Given the wide dynamic range between the Homunculus and the central source, we will employ a strategy successfully applied to HST WFPC2 polarization observations of the Eta Carinae nebula by Schulte-Ladbeck, Clampin and Hillier (HST Prop. 5840) who obtained three images exposed to different signal levels. The following WFPC2 images will be obtained:, WFPC2 Exposure Sequence Filter Short Intermediate Long F656N 1 sec 10 secs 200 secs F487N 1 sec 20 secs 400 secs F547M 1 sec 5 secs 40 secs These observations will require 38.5 minutes, including the 3 minute overhead for each observation. The NICMOS observations will all be made using the MULTIACCUM mode of observation with appropriate SAMP-TIMEs to provide 1 sec, 10 sec, and 100 sec intermediate readouts. This approach allows us to obtain unsaturated images of the central core, and then to saturate the core to obtain sufficient signal to noise in the outer regions of the Homonculus. MULTIACCUM is the optimum NICMOS observing mode for sources with wide dynamic range. Since the set of filters we require are not all available for one camera, the majority of our observations are concentrated in Camera 2, while the Fe II line imaging and polarization measurements will be made with Camera 1. The Fe II line images will be rebinned where necessary. The exposure times have been calculated to ensure that a signal to noise of at least 20 is obtained in the line images, once the continuum is subtracted. The emission line and continuum fluxes, when available, were obtained from Allen et al (1985), Hamann et al. and Allen (1989). Example line fluxes are shown below. BGamma 125 x 10^-11 ergs/s/cm^2 Fe II 67 x 10^-11 ergs/s/cm^2 In order to measure the background level, we will use a ONE-CHOP pattern for observations with filters where thermal background is present. The following observing sequence is planned: Item Location Filter NICMOS Camera Exposure time PAlpha Source F187N Camera 2 200 secs PAlpha Sky F187N Camera 2 200 secs PAlpha c Sky F190N Camera 2 200 secs PAlpha c Source F190N Camera 2 200 secs BGamma Source F216N Camera 2 200 secs BGamma c Sky F216N Camera 2 200 secs BGamma Sky F215N Camera 2 200 secs BGamma c Source F215N Camera 2 200 secs H_2 Source F212N Camera 2 200 secs H_2 Sky F212N Camera 2 200 secs CO c Sky F227N Camera 2 200 secs CO c Source F227N Camera 2 200 secs CO Source F237N Camera 2 200 secs CO Sky F237N Camera 2 200 secs FeII Source F164N Camera 1 600 secs FeII c Source F166N Camera 1 600 secs Pol 0^o Source POL0S Camera 1 100 secs Pol 120^o Source POL120S Camera 1 100 secs Pol 140^o Source POL240S Camera 1 100 secs Unpol c Source F110M Camera 1 100 secs The BGamma and H_2 filters share the same continuum filter. These NICMOS observations require a total of 128 minutes, with the inclusion of instrumental overheads, the slews and re- acquisitions for four ONE-CHOP patterns and NICMOS camera changes. The total observation time required, including a 9 minute acquistion and a 6 minute re-acqusition is 2 CVZ orbits. Flux References Allen, D. A. 1989, M.N.R.A.S 241, 195 Allen, D. A., Jones, T. J. and Hyland, A. R. 1985, Ap.J 291, 280., Hamann, F., DePoy D. L., Johansson, S. & Elias J, Ap. J, 422, 626. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 3] Data Distribution Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ETA-CAR Star, Luminous Blue RA=10H 45M 03.656S +/- 0S, DEC=- J2000 V = 6.2 Variable 59D 41' 02.813" +/- 0" B-V = 0.6 2 ETA-CAR-2 Star, Luminous Blue RA=10H 45M 03.656S +/- 0S, DEC=- J2000 V = 6.2 Variable 59D 41' 02.813" +/- 0" B-V = 0.6 7323( 6) - 12/31/97 14:34 - [ 5] Visit: 01 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 ETA-CAR WFPC2 IMAGE PC1 F547M 1 0.3 S ------------------------------------------------------------------------------------------------------------------------------------ 11 ETA-CAR WFPC2 IMAGE PC1 F547M 1 5 S ------------------------------------------------------------------------------------------------------------------------------------ 12 ETA-CAR WFPC2 IMAGE PC1 F547M 1 40 S ------------------------------------------------------------------------------------------------------------------------------------ 13 ETA-CAR WFPC2 IMAGE PC1 F487N 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 14 ETA-CAR WFPC2 IMAGE PC1 F487N 1 20 S ------------------------------------------------------------------------------------------------------------------------------------ 15 ETA-CAR WFPC2 IMAGE PC1 F487N 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 16 ETA-CAR WFPC2 IMAGE PC1 F656N 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 17 ETA-CAR-2 WFPC2 IMAGE PC1 F656N 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 18 ETA-CAR WFPC2 IMAGE PC1 F656N 1 200 S ------------------------------------------------------------------------------------------------------------------------------------ 19 ETA-CAR NIC1 MULTIAC NIC1 F110M SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 20 ETA-CAR NIC1 MULTIAC NIC1 F110M SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 21 ETA-CAR NIC1 MULTIAC NIC1 POL0S SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 22 ETA-CAR NIC1 MULTIAC NIC1 POL120S SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 23 ETA-CAR NIC1 MULTIAC NIC1 POL240S SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 24 ETA-CAR NIC1 MULTIAC NIC1 F164N SAMP-SEQ=SPARS256,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 25 ETA-CAR NIC1 MULTIAC NIC1 F166N SAMP-SEQ=SPARS256,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 30 ETA-CAR NIC2 MULTIAC NIC2 F187N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 32 ETA-CAR NIC2 MULTIAC NIC2 F190N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 34 ETA-CAR NIC2 MULTIAC NIC2 F216N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 36 ETA-CAR NIC2 MULTIAC NIC2 F215N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 38 ETA-CAR NIC2 MULTIAC NIC2 F212N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 40 ETA-CAR NIC2 MULTIAC NIC2 F237M SAMP-SEQ=MIF1024,NSAMP=11, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 42 ETA-CAR NIC2 MULTIAC NIC2 F222M SAMP-SEQ=MIF1024,NSAMP=11, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 7] Visit: 02 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 ETA-CAR-2 WFPC2 IMAGE PC1 F547M 1 0.3 S ------------------------------------------------------------------------------------------------------------------------------------ 11 ETA-CAR-2 WFPC2 IMAGE PC1 F547M 1 5 S ------------------------------------------------------------------------------------------------------------------------------------ 12 ETA-CAR-2 WFPC2 IMAGE PC1 F547M 1 40 S ------------------------------------------------------------------------------------------------------------------------------------ 13 ETA-CAR-2 WFPC2 IMAGE PC1 F487N 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 14 ETA-CAR-2 WFPC2 IMAGE PC1 F487N 1 20 S ------------------------------------------------------------------------------------------------------------------------------------ 15 ETA-CAR-2 WFPC2 IMAGE PC1 F487N 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 16 ETA-CAR-2 WFPC2 IMAGE PC1 F656N 1 0.5 S ------------------------------------------------------------------------------------------------------------------------------------ 17 ETA-CAR-2 WFPC2 IMAGE PC1 F656N 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 18 ETA-CAR-2 WFPC2 IMAGE PC1 F656N 1 200 S ------------------------------------------------------------------------------------------------------------------------------------ 19 ETA-CAR-2 NIC1 MULTIAC NIC1 F110M SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 20 ETA-CAR-2 NIC1 MULTIAC NIC1 F110M SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 21 ETA-CAR-2 NIC1 MULTIAC NIC1 POL0S SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 22 ETA-CAR-2 NIC1 MULTIAC NIC1 POL120S SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 23 ETA-CAR-2 NIC1 MULTIAC NIC1 POL240S SAMP-SEQ=MIF1024,NSAMP=10 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 24 ETA-CAR-2 NIC1 MULTIAC NIC1 F164N SAMP-SEQ=SPARS256,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 25 ETA-CAR-2 NIC1 MULTIAC NIC1 F166N SAMP-SEQ=SPARS256,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 30 ETA-CAR-2 NIC2 MULTIAC NIC2 F187N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 32 ETA-CAR-2 NIC2 MULTIAC NIC2 F190N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 34 ETA-CAR-2 NIC2 MULTIAC NIC2 F216N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 36 ETA-CAR-2 NIC2 MULTIAC NIC2 F215N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 38 ETA-CAR-2 NIC2 MULTIAC NIC2 F212N SAMP-SEQ=MIF1024,NSAMP=12, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 40 ETA-CAR-2 NIC2 MULTIAC NIC2 F237M SAMP-SEQ=MIF1024,NSAMP=11, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 42 ETA-CAR-2 NIC2 MULTIAC NIC2 F222M SAMP-SEQ=MIF1024,NSAMP=11, 1 DEF CUM PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=40,PATTERN-ORIENT=90 Comments: Please ensure that orientation for chopping is at PA=0 ------------------------------------------------------------------------------------------------------------------------------------ 7323( 6) - 12/31/97 14:34 - [ 9] Summary Form for Proposal 7323 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 NIC1 NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=MIF1024 NSAMP=10 NSAMP=5 SAMP-SEQ=SPARS256 PATTERN-ORIENT=90 CHOP-SIZE=40 NUM-POS=2 PATTERN=ONE-CHOP NSAMP=12 NSAMP=11 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F547M F487N F656N F110M POL0S POL120S POL240S F164N F166N F187N F190N F216N F215N F212N F237M F222M ------------------------------------------------------------------------------------------------------------------------------------ Target Names ETA-CAR ETA-CAR-2 ------------------------------------------------------------------------------------------------------------------------------------