8279( 8) - 02/07/00 16:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8279 Version: 8 Check-in Date: 07-Feb-2000 16:15:06 1.Proposal Title: Cataclysmic Variable Disk Winds: a high time- and spectral resolution study of flow inhomogeneity ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Janet Drew Imperial College of Science Technology and Medicine CoI: Dr. Knox Long Space Telescope Science Institute Y CoI: Dr. Christian Knigge Space Telescope Science Institute N CoI: Dr. Daniel Proga Imperial College of Science, Technology & N Medicine CoI: Dr. James Stone University of Maryland N ------------------------------------------------------------------------------------ 5. Abstract Disks and disk winds are found in many astrophysical settings. While much effort has been invested in models for centrifugal MHD disk winds over the past decade or so, only within the past year has the modelling of radiation-driven disk winds developed to the point of generating predictions. This proposed programme of time-resolved UV STIS/E140M observations of the high-state non-magnetic cataclysmic variables (hNCV), IX Vel, V3885 Sgr, and QU Car, will explore a striking prediction of the line-driven wind simulations by Proga et al (1998). These have shown that unsteady, clumped outflow is to be expected where most of the driving luminosity is produced by the disk rather than the central star -- a circumstance believed to apply in hNCV. This programme will identify such clumping as narrow absorption features, first appearing at low outflow velocities, superposed on UV wind-formed spectral line profiles. In addition, these winds, if line-driven, are likely at higher proje cted outflow velocities to prompt further moving narrow absorption components analogous to those well- known in OB stellar spectra. Flow times are so short (~ 50 sec) in these compact binaries that time-tagged HST/STIS observation is the only option. Observing 3 targets at 3 epochs will both confront theory directly and yield insights into the systematic trends needed to build our understanding of line-driven disk winds. ------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 2] Observations Description ------------------------ Our proposed targets are IX Vel, V3885 Sgr, and QU Car. These are all hNCV, classified as novalike variables, that have been observed repeatedly with IUE. The spectra shown in Fig.\ 2 are typical. Of all cataclysmic variable sub- classes, novalike variables are perhaps the simplest because their disks are always in high mass-transfer states. This makes observations of non-eclipsing examples straightforward because their UV flux and spectra do not change greatly from epoch to epoch. These three were selected because they are among the brightest and best studied (IX Vel: Long et al. 1994, V3885 Sgr: Prinja & Rosen 1995, Woods et al. 1992, QU Car: Knigge et al. 1994), because they have relatively low inclination and -- most important -- because their UV line features are clearly seen, but not completely saturated. It is because of obvious line saturation that we do not include the bright hNCV RW Sex as a proposed target. We propose to observe each object 3 times at interv als separated by at least a month. The strength of the wind lines varies from month to month in these and other novalikes and it is important to ensure that the systems have not been observed in an unusual state. Single orbit observations with exposure times estimated to be 1900, 2150, and 2400 s for IX Vel, V3885 Sgr, and QU Car will enable our time-variability studies and will in addition produce superb time-averaged high resolution spectra. The observations we propose would be carried out with STIS using the FUV MAMA and the E140M grating covering the wavelength range 1150-1710 Angstrom . This range encompasses lines produced by a variety of ions, including C iii Lambda1176, N v Lambda1240, Si iii Lambda1300, Si iv Lambda1397, C iv Lambda1549 and He ii Lambda1640. As a result of the different ionization potentials involved, these will probe different regions within the wind. Because the principle focus of our study is on wind variability, the observations will be carried in the high time resoluti on mode. We have used the spectra in fig.\ 2 and the STIS ETC to estimate countrates. In general, we want to maximize the countrate subject to the need to remain below the global (30, 000 counts s^-1) limit established by non- linearity and data storage limits. For the two less-bright sources, V3885 Sgr and QU Car, we would use the higher throughput 0.2 x 0.2 arcsec slit. In that case, we expect global rates to be 17, 300 s^-1 and 7, 200 s^-1, respectively. For IX Vel, the ETC estimates produce a global rate of 30, 000 s^-1 with the 0.2 x 0.06 arcsecond slit, and so for IX Vel, we would use the 0.1 x 0.03 arcsec slit to drop the rate to 20, 000 s^-1. With these configurations, local count rates for V3885 Sgr at N v Lambda1240, Si iv Lambda 1397, and C iv Lambda1550 are 18, 29, and 13 counts s^-1 AA^-1. The spectra of IX Vel and QU Car have similar spectral shapes and therefore their local rates can be estimated directly from the ratio of global count rates. Since we propose that the spectra be obtained in photon counting mode, there wi ll be considerable flexibility in that the spectral resolution and timescale on which we can measure line profiles can be viewed as inversely related to one another. For example, for V3885 Sgr, at 1240 Angstrom\ and 1 Angstrom\ (250 km s^-1) effective resolution, we would expect to measure line profiles with 10\ 0.5 Angstrom\ resolution, 24 seconds will be required. The timescales we really need to explore will only become obvious from the data themselves. We are confident that the flexibility of our chosen STIS configuration provides the right platform for attaining the observational goals of this programme. Real Time Justification ----------------------- None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 3] Data Distribution Paper Products: YES Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 IX-VEL STAR, NOVA-LIKE, STAR RA=8H 15M 18.90S +/- 0.6", DEC=- J2000 F(1450)=7+/-1e-12 49D 13' 18.3" +/- 0.6", PLATE- V = 9.5+/-0.4 ID=03DQ Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1975.201 -0.00275084 -0.09582 0.0 2 V3885SGR STAR, NOVA-LIKE RA=19H 47M 40.54S +/- 0.6", DEC= J2000 F(1450)=3.4+/-0.4e-12 -42D 0' 25.5" +/- 0.6", PLATE- V = 10.0+/-0.4 ID=01CE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1976.434 0.00251661 -0.0406 0.0 3 QU-CAR STAR, NOVA-LIKE RA=11H 5M 42.8S +/- 0.6", DEC=- J2000 F(1450)=1.2+/-0.2e-12 68D 37' 58.0" +/- 0.6", PLATE- V = 11.3+/-0.2 ID=0197 8279( 8) - 02/07/00 16:16 - [ 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 IX-VEL STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 IX-VEL STIS/C ACQ/PEA 0.2X0.2 MIRROR 1 0.1 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 30 IX-VEL STIS/C ACQ/PEA 0.1X0.0 MIRROR 1 0.1 S CD K 3 ------------------------------------------------------------------------------------------------------------------------------------ 40 IX-VEL STIS/F TIME-TA 0.1X0.0 E140M 1425 BUFFER-TIME=99 1 1750 S UV-MAM G 3 A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 6] Visit: 02 Visit Priority: Visit Requirements: AFTER 01 BY 30 D 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 IX-VEL STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 IX-VEL STIS/C ACQ/PEA 0.2X0.2 MIRROR 1 0.1 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 30 IX-VEL STIS/C ACQ/PEA 0.1X0.0 MIRROR 1 0.1 S CD K 3 ------------------------------------------------------------------------------------------------------------------------------------ 40 IX-VEL STIS/F TIME-TA 0.1X0.0 E140M 1425 BUFFER-TIME=99 1 1750 S UV-MAM G 3 A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 7] Visit: 03 Visit Priority: Visit Requirements: AFTER 02 BY 30 D 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 IX-VEL STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 IX-VEL STIS/C ACQ/PEA 0.2X0.2 MIRROR 1 0.1 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 30 IX-VEL STIS/C ACQ/PEA 0.1X0.0 MIRROR 1 0.1 S CD K 3 ------------------------------------------------------------------------------------------------------------------------------------ 40 IX-VEL STIS/F TIME-TA 0.1X0.0 E140M 1425 BUFFER-TIME=99 1 1750 S UV-MAM G 3 A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 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 V3885SGR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 V3885SGR STIS/F TIME-TA 0.2X0.2 E140M 1425 BUFFER-TIME=99 1 2480 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 9] Visit: 05 Visit Priority: Visit Requirements: AFTER 04 BY 30 D 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 V3885SGR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 V3885SGR STIS/F TIME-TA 0.2X0.2 E140M 1425 BUFFER-TIME=99 1 2480 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 10] Visit: 06 Visit Priority: Visit Requirements: AFTER 05 BY 30 D 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 V3885SGR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 V3885SGR STIS/F TIME-TA 0.2X0.2 E140M 1425 BUFFER-TIME=99 1 2480 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 11] Visit: 07 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 QU-CAR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S ONBOARD ACQ FOR 30 CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 QU-CAR STIS/F TIME-TA 0.2X0.2 E140M 1425 BUFFER-TIME=99 1 2300 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 12] Visit: 08 Visit Priority: Visit Requirements: AFTER 07 BY 30 D 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 QU-CAR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 QU-CAR STIS/F TIME-TA 0.2X0.2 E140M 1425 BUFFER-TIME=99 1 2600 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 13] Visit: 09 Visit Priority: Visit Requirements: AFTER 08 BY 30 D 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 QU-CAR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 QU-CAR STIS/F TIME-TA 0.2X0.2 E140M 1425 BUFFER-TIME=99 1 2600 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8279( 8) - 02/07/00 16:16 - [ 14] Summary Form for Proposal 8279 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 0.1X0.03 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT BUFFER-TIME=99 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 30 D AFTER 02 BY 30 D AFTER 04 BY 30 D AFTER 05 BY 30 D ONBOARD ACQ FOR 30 AFTER 07 BY 30 D AFTER 08 BY 30 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names IX-VEL V3885SGR QU-CAR ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 ------------------------------------------------------------------------------------------------------------------------------------