6796( 9) - 08/30/96 10:11 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6796 Version: 9 Check-in Date: 30-Aug-1996 11:06:31 1.Proposal Title: Spectral Mapping of Accretion Disks in Cataclysmic Binaries: Bridging the CV Period Gap ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle BINARIES AND STAR FOR GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: RAYMUNDO BAPTISTA UNIVERSIDADE FEDERAL DE SANTA CATARINA/UFSC CoI: Rene Rutten Royal Greenwich Observatory - La Palma N CoI: Richard Wade Pennsylvania State University N CoI: Keith Horne University of St Andrews N CoI: Ivan Hubeny NASA Goddard Space Flight Center N CoI: Knox Long Space Telescope Science Institute N CoI: Christopher Mauche Lawrence Livermore National Laboratory N ------------------------------------------------------------------------------------ 6. Abstract Maximum-entropy eclipse mapping techniques have advanced to the stage of delivering spatially-resolved spectra of accretion disks. By fitting disk model atmospheres to these spectra we are now able to determine the radial run of the temperature, surface density (which controls the local effective gravity of the disk), Mach number (which controls the strength of Balmer lines vs Balmer continuum), and the vertical temperature gradient in the disk (which controls whether the lines are in emission or absorption). Accretion disks in Cataclysmic Variables (CVs) cover a range of accretion rates and viscosity states. CVs show a bi-modal distribution of orbital periods, with systems clustering at periods of 1.5-2 hr or 3-5 hr, and a remarkable dearth of systems with periods between 2-3 hr. Our previous HST mapping experiments have framed accretion disks on both sides of this period gap, corresponding to the low and high accretion regimes. We now propose to look inside the gap by mapping the disk of V348 Pup (P_orb= 2.44 hr). There are evidences that its disk has different properties from those previously mapped by HST at shorter and longer periods. Observations of this type can drive fundamental new insights into the physics of accretion disks. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to observe 8 eclipses of V348 Pup. To have the broadest possible spectral coverage we will combine 4 visits with FOS/BL G160L (1150 to 2500 Angstrom) to 4 visits with FOS/RD PRISM (1800 to 8500 Angstrom). We are primarily interested in studying continuum and emission line time variability, and therefore we will use the FOS in the ``RAPID'' mode to obtain high temporal resolution. Ideally we would like to observe from binary phase -0.13 to +0.13 for each eclipse. This requires 39-min for V348 Pup (P_orb= 146 -min). We need to observe the eclipse 4 times (for each disperser) because this will distinguish between variations due to the eclipse of the WD and accretion disk and those due to flickering -- which is known to be present in this system at optical wavelengths -- and also because it allow us to increase the signal-to- noise ratio (S/N) of the eclipse light curves in each spectral bin by combining the 4 individual eclipses. The proposed sequence of observations consists of one HST orbit for a target acquisition with the ACQ/PEAK procedure (41 min), followed by a science exposure of 44 min in the next orbit. The second visit should be spaced by at least 3 days to allow the use of the ``reuse\\_target\\_offset'' procedure. All consecutive visits will than consist of one science exposure of 41/42 mins per orbit. The 8 exposures should be spaced as closely as possible in time (and by no more than 3-4 weeks to permit use of ``reuse\\_target\\_offset'') consistent with the requirement to obtain the appropriate phase coverage. The exposure times are dictated by the time to cover the eclipse of V348 Pup. We estimate a count rate of 0.17 counts/s/Angstrom at 1850 Angstrom using continuum fluxes from an IUE spectrum (SWP 44676, 1.3* 10^-14 ergs/cm^2/s/Angstrom) and the latest sensitivity data on the FOS using the 0.9 arcsec (1.0) aperture. Thus 50 Angstrom wide bandpasses will yield UV light curves with a S/N of 10 in 12 s integrations. The C IV line has a flux of 7* 10^-13 ergs/cm^2/s and will produce 65 counts/s (S/N = 8). These numbers increase by a factor 2 by combining the 4 individual eclipses in average eclipse light curves. Real Time Justification ----------------------- These observations are time-critical and must cover specific orbital phases. The orbital ephemeris of V348 Pup is well known so the conditions can be specified well in advance. The target is not a dwarf nova and therefore it does not undergo the periodic outbursts associated with those objects. However, since it is expected to present some low amplitude variations (~lt 0.5 mag), all 8 observations should be scheduled as close as possible in time to minimize the effects of secular variations and the joining together of the light curves from the various eclipses. Whole eclipses must be observed whenever possible. Calibration Justification ------------------------- Additional Comments ------------------- The 8 science exposures should be obtained by alternating between exposures using the FOS/BL,G160L and FOS/RD,PRISM configurations. To allow simultaneous ground-based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS STAR, NOVA-LIKE, RA=07H 12M 32.90S +/- 0.5", DEC= J2000 V = 15.6+/-0.4 INTERACTING BINARY, -36D 05' 39.6" +/- 0.5", PLATE- U-B = -0.65+/-0.15 ACCRETION DISK ID=02CS B-V = +0.15+/-0.15 V-R = +0.15+/-0.15 F-CONT(1850)=1.3+/-0.5e-14 Comments: Eclipsing nova-like variable; flux ranges reflect the range of variations outside of eclipses. Target acquisition will occur outside of eclipse. 6796( 9) - 08/30/96 10:11 - [ 2] Visit: 01 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 On Hold Comments: Additional Comments: To allow simultaneous ground-based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 V348-PUPPIS FOS/RD ACQ/PEA 4.3 MIRROR SCAN-STEP-Y=1.23,SEARCH-SIZE-X=1, 1 1 S ONBOARD ACQ FOR 20 K SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 20 V348-PUPPIS FOS/RD ACQ/PEA 1.0-PAI MIRROR SCAN-STEP-X=0.61,SCAN-STEP-Y=0.61 1 1 S ONBOARD ACQ FOR 30 K R-A ,SEARCH-SIZE-X=6,SEARCH-SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 30 V348-PUPPIS FOS/RD ACQ/PEA 0.5-PAI MIRROR SCAN-STEP-X=0.29,SCAN-STEP-Y=0.29 1 1 S ONBOARD ACQ FOR 40 K R-A ,SEARCH-SIZE-X=3,SEARCH-SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 40 V348-PUPPIS FOS/RD ACQ/PEA 0.25-PA MIRROR SCAN-STEP-X=0.11,SCAN-STEP-Y=0.11 1 4 S ONBOARD ACQ FOR 50; SAVE K IR-A ,SEARCH-SIZE-X=4,SEARCH-SIZE-Y=4 OFFSET OFF-1 Comments: If possible, use occultation time to switch Sp_Element to PRISM and Aperture to 4.3 to save time for next orbit exposure. ------------------------------------------------------------------------------------------------------------------------------------ 50 V348-PUPPIS FOS/RD RAPID 1.0-PAI PRISM SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2530 S NO SPLIT; PHASE 0.86 TO R-A STEP-PATT=SINGLE 0.14 Comments: Try to center exposure on phase 0.0 Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 3] Visit: 02 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D SEQ 2-8 WITHIN 25D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/BL RAPID 1.0-PAI G160L SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2375 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 4] Visit: 03 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/RD RAPID 1.0-PAI PRISM SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2305 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 5] Visit: 04 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/BL RAPID 1.0-PAI G160L SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2375 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 6] Visit: 05 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/RD RAPID 1.0-PAI PRISM SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2305 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 7] Visit: 06 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/BL RAPID 1.0-PAI G160L SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2375 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 8] Visit: 07 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/RD RAPID 1.0-PAI PRISM SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2305 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 9] Visit: 08 Visit Requirements: PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D On Hold Comments: Additional Comments: Use of USE OFFSET constrain separation with respect to first visit. All visits thereafter should be scheduled as close as possible in time consistent with the PHASE requirements, and in a sequence alternating exposures with FOS/BL,G160L and FOS/RD,PRISM. To allow simultaneous ground- based optical observations, we prefer that these observations are scheduled (in order of preference) during the October/November, September, or December/January scheduling windows. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V348-PUPPIS FOS/BL RAPID 1.0-PAI G160L SUB-STEP=2,READ-TIME=5,COMB=YES, 1 2375 S NO SPLIT; PHASE 0.87 TO R-A STEP-PATT=SINGLE 0.13 USE OFFSET OFF-1 Comments: Try to center exposure on phase 0.0. Uninterrupted eclipse coverage required. ------------------------------------------------------------------------------------------------------------------------------------ 6796( 9) - 08/30/96 10:11 - [ 10] Summary Form for Proposal 6796 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK RAPID ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=1.23 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 SEARCH-SIZE-Y=2 SEARCH-SIZE-X=3 SEARCH-SIZE-Y=4 STEP-PATT=SINGLE COMB=YES READ-TIME=5 SUB-STEP=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category BINARIES AND STAR FORMATION ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 ONBOARD ACQ FOR 20 ONBOARD ACQ FOR 30 ONBOARD ACQ FOR 40 ONBOARD ACQ FOR 50; SAVE OFFSET OFF-1 NO SPLIT; PHASE 0.86 TO 0.14 PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D SEQ 2-8 WITHIN 25D NO SPLIT; PHASE 0.87 TO 0.13 USE OFFSET OFF-1 PERIOD 0.101838911D AND ZERO-PHASE JD2447210.12101 AFTER 1 BY 3D TO 28D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR PRISM G160L ------------------------------------------------------------------------------------------------------------------------------------ Target Names V348-PUPPIS ------------------------------------------------------------------------------------------------------------------------------------