9686( 12) - 07/14/03 19:49 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9686 Version: 12 Check-in Date: 14-Jul-2003 19:46:09 1.Proposal Title: Probing the Accretion Geometry of a Quiescent Black Hole ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Dr. Robert I. Hynes University of Texas at Austin CoI: Dr. Jorges Casares Instituto de Astrofisica de Canarias N CoI: Prof. Philip A. Charles University of Southampton N CoI: Dr. Rob Fender Universiteit van Amsterdam N CoI: Dr. Mike R Garcia Harvard University N CoI: Dr. Carole A. Haswell Open University N CoI: Dr. Albert Kong Smithsonian Institution Astrophysical N Observatory CoI: Dr. Jeffrey E. McClintock Smithsonian Institution Astrophysical N Observatory CoI: Prof. Edward L. Robinson University of Texas at Austin N CoI: Dr. Tariq Shahbaz Instituto de Astrofisica de Canarias N CoI: Dr. Cristina Zurita Institute de Astrofis de Canarias N ------------------------------------------------------------------------------------ 5. Abstract Advective accretion is invoked to explain low luminosity accretion onto both stellar mass and supermassive black holes. There has been much theoritcal activity, and controversy, but observational constraints are weak. We have found considerable x- ray and optical variability. The similarity of timescales and amplitudes, and the emission line kinematics all suggest that the optical variability is driven by x-ray illumination of the accretion disc. We now propose the first simultaneous x-ray and optical observations to test if the variations are correlated and measure relative amplitudes. Our program will yield new constraints upon the models, as the strength of the optical emission line response is sensitive to the unobservable EUV spectrum, and to the x-ray emission geometry. ------------------------------------------------------------------------------------ 9686( 12) - 07/14/03 19:49 - [ 2] Observations Description ------------------------ Our primary goal is to obtain time-resolved near-UV photometry of the quiescent black hole candidate V404 Cyg, in parallel with Chandra X-ray monitoring and optical spectroscopy. The UV observations are crucial as they trace uncontaminated accretion continuum, whereas the optical continuum is dominated by the K0IV companion star. We wish to obtain as near to continuous monitoring of V404 Cyg for the awarded 5 orbits as possible. Consequently, the visit structure below is driven by the need to fill the available time as completely as possible, not by a requisite signal-to-noise. The number of iterations and/or the exposure times should be adjusted as necessary to fill the actual available time when the scheduling is known, maintaining an exposure time of approximately 200s. ACS is well suited to our science, with a low background rate and the HRC/F250W effective bandpass 2400-3200A. Adopting the model spectrum from Narayan et al. (1997) as representative, we estimate that with this configuration we can achieve a signal-to-noise ratio of 12.6 in a 200s exposure. Since both X-rays and Halpha exhibit changes of a factor of two, and the optical continuum likely varies by a similar amount when corrected for the companion star contribution, it is reasonable to also expect such changes in the UV continuum. These will be easily detectable; for comparison, the predicted Chandra signal-to-noise ratio for 200s is only 5.4, yet X-ray variations can easily be seen in these data. 200s is chosen not only based on the signal-to-noise per image, but also on the need to minimise the total time spent reading out the CCD. Our secondary goal is to obtain UV photometry to contribute to the broad-band spectral energy distribution of the source. This becomes the primary goal of any visits not schedulable simultaneously with Chandra. For these visits we alternate filters, HRC/F330W and HRC/F250W to obtain multiple estimates of the near-UV color. Repetition and interleaving are essential as the source is variable on timescales of minutes to hours. Since the target is red, Real Time Justification ----------------------- Simultaneous multiwavelength observations are essential to our science and form the primary goal of our program. Consequently, HST observations must be scheduled at some point during the Chandra observations as far as is possible. Chandra observations are scheduled for 2003 July 28 21:00 to July 29 15:00. Optical and radio observations are also scheduled in and around the radio window, but do not further constrain the HST scheduling. Any visits which cannot be coordinated with the Chandra window should be scheduled as close to it as possible, subject to achieving reasonable visibility. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9686( 12) - 07/14/03 19:49 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V404-CYG STAR, INTERACTING RA=20H24M3.78S +/- 0.08S, J2000 V = 18.42+/-0.02 BINARY, LMXB DEC=+33D52'3.2" +/- 1.0" B-V = 2.21+/-0.07 E(B-V) = 1.3+/-0.2 Coordinate Source: Other_Source: A catalog and atlas of cataclysmic variables: the living edition (Downes et al. 2001, PASP, 113, 764) Comments: UV brightness unknown 9686( 12) - 07/14/03 19:49 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.15 Coordinate_Frame POS-TARG Pattern_Orient 19.89 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.198 Coordinate_Frame POS-TARG Pattern_Orient 44.28 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 9686( 12) - 07/14/03 19:49 - [ 5] Visit: 01 Visit Priority: Visit Requirements: SAME ORIENT AS 04 BETWEEN 28-JUL-2003:21:00:00 AND 29-JUL-2003:06:58:00 VISIBILITY INTERVAL 30 M On Hold Comments: Additional Comments: We wish as near continuous cycling of images as possible. Exact exposure times should be adjusted to pad the available time when the scheduling is known, maintaining the four-point pattern. Must be simultaneous with Chandra; Chandra windows 28 July (2003.209:21:00:00) to 29 July (2003.210:15:00:00). NOTE: Updated BETWEEN - RAL - 03/27/03. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 245 S PATTERN 1 1 C ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 1 none none none 1 tbd 01 1 2 none none none 1 tbd 01 1 3 none none none 1 tbd 01 1 4 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 6] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENT AS 04 BETWEEN 28-JUL-2003:21:00:00 AND 29-JUL-2003:06:58:00 VISIBILITY INTERVAL 30 M On Hold Comments: Additional Comments: We wish as near continuous cycling of images as possible. Exact exposure times should be adjusted to pad the available time when the scheduling is known, maintaining the four-point pattern. Must be simultaneous with Chandra; Chandra windows 28 July (2003.209:21:00:00) to 29 July (2003.210:15:00:00). NOTE: Updated BETWEEN - RAL - 03/27/03. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 245 S PATTERN 1 1 C ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 1 none none none 1 tbd 02 1 2 none none none 1 tbd 02 1 3 none none none 1 tbd 02 1 4 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 7] Visit: 03 Visit Priority: Visit Requirements: SAME ORIENT AS 04 BETWEEN 28-JUL-2003:21:00:00 AND 29-JUL-2003:06:58:00 VISIBILITY INTERVAL 30 M On Hold Comments: Additional Comments: We wish as near continuous cycling of images as possible. Exact exposure times should be adjusted to pad the available time when the scheduling is known, maintaining the four-point pattern. Must be simultaneous with Chandra; Chandra windows 28 July (2003.209:21:00:00) to 29 July (2003.210:15:00:00). NOTE: Updated BETWEEN - RAL - 03/27/03. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 245 S PATTERN 1 1 C ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 03 1 1 none none none 1 tbd 03 1 2 none none none 1 tbd 03 1 3 none none none 1 tbd 03 1 4 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 8] Visit: 04 Visit Priority: Visit Requirements: BETWEEN 28-JUL-2003:00:00:00 AND 29-JUL-2003:00:00:00 On Hold Comments: Additional Comments: Individual exposure times should be increased or decreased as necessary to match the exact observing window, i.e. add or subtract 1/12th of the time difference from each exposure. If possible, Visits 04 and 05 should be done before and as close as possible to the Chandra coordinated visits, Visits 01-03, and on the same calendar. Second choice is late in the previous week's calendar, and third choice is ASAP after Visits 01-03 and the SAA impacts that follow them. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V404-CYG ACS/HR ACCUM HRC F330W CR-SPLIT=NO 1 100 S PATTERN 2 1 C ------------------------------------------------------------------------------------------------------------------------------------ 2 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 200 S PATTERN 2 2 C ------------------------------------------------------------------------------------------------------------------------------------ 3 V404-CYG ACS/HR ACCUM HRC F330W CR-SPLIT=NO 1 100 S PATTERN 2 3 C ------------------------------------------------------------------------------------------------------------------------------------ 4 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 200 S PATTERN 2 4 C ------------------------------------------------------------------------------------------------------------------------------------ 5 V404-CYG ACS/HR ACCUM HRC F330W CR-SPLIT=NO 1 100 S PATTERN 2 5 C ------------------------------------------------------------------------------------------------------------------------------------ 6 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 200 S PATTERN 2 6 C ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 04 1 1 none none none 1 tbd 04 1 2 none none none 1 tbd 04 2 1 none none none 1 tbd 04 2 2 none none none 1 tbd 04 3 1 none none none 1 tbd 04 3 2 none none none 1 tbd 04 4 1 none none none 1 tbd 04 4 2 none none none 1 tbd 04 5 1 none none none 1 tbd 04 5 2 none none none 1 tbd 04 6 1 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 9] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 04 6 2 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 10] Visit: 05 Visit Priority: Visit Requirements: SAME ORIENT AS 04 BETWEEN 28-JUL-2003:00:00:00 AND 29-JUL-2003:00:00:00 On Hold Comments: Additional Comments: Individual exposure times should be increased or decreased as necessary to match the exact observing window, i.e. add or subtract 1/12th of the time difference from each exposure. If possible, Visits 04 and 05 should be done before and as close as possible to the Chandra coordinated visits, Visits 01-03, and on the same calendar. Second choice is late in the previous week's calendar, and third choice is ASAP after Visits 01-03 and the SAA impacts that follow them. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V404-CYG ACS/HR ACCUM HRC F330W CR-SPLIT=NO 1 100 S PATTERN 2 1 C ------------------------------------------------------------------------------------------------------------------------------------ 2 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 200 S PATTERN 2 2 C ------------------------------------------------------------------------------------------------------------------------------------ 3 V404-CYG ACS/HR ACCUM HRC F330W CR-SPLIT=NO 1 100 S PATTERN 2 3 C ------------------------------------------------------------------------------------------------------------------------------------ 4 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 200 S PATTERN 2 4 C ------------------------------------------------------------------------------------------------------------------------------------ 5 V404-CYG ACS/HR ACCUM HRC F330W CR-SPLIT=NO 1 100 S PATTERN 2 5 C ------------------------------------------------------------------------------------------------------------------------------------ 6 V404-CYG ACS/HR ACCUM HRC F250W CR-SPLIT=NO 1 200 S PATTERN 2 6 C ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 05 1 1 none none none 1 tbd 05 1 2 none none none 1 tbd 05 2 1 none none none 1 tbd 05 2 2 none none none 1 tbd 05 3 1 none none none 1 tbd 05 3 2 none none none 1 tbd 05 4 1 none none none 1 tbd 05 4 2 none none none 1 tbd 05 5 1 none none none 1 tbd 05 5 2 none none none 1 tbd 05 6 1 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 11] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 05 6 2 none none none 1 tbd 9686( 12) - 07/14/03 19:49 - [ 12] Summary Form for Proposal 9686 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures HRC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SAME ORIENT AS 04 BETWEEN 28-JUL-2003 21 00 00 AND 29-JUL-2003 06 58 00 VISIBILITY INTERVAL 30 M PATTERN 1 1 SAME ORIENT AS 04 BETWEEN 28-JUL-2003 21 00 00 AND 29-JUL-2003 06 58 00 VISIBILITY INTERVAL 30 M SAME ORIENT AS 04 BETWEEN 28-JUL-2003 21 00 00 AND 29-JUL-2003 06 58 00 VISIBILITY INTERVAL 30 M BETWEEN 28-JUL-2003 00 00 00 AND 29-JUL-2003 00 00 00 PATTERN 2 1 PATTERN 2 2 PATTERN 2 3 PATTERN 2 4 PATTERN 2 5 PATTERN 2 6 SAME ORIENT AS 04 BETWEEN 28-JUL-2003 00 00 00 AND 29-JUL-2003 00 00 00 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F250W F330W ------------------------------------------------------------------------------------------------------------------------------------ Target Names V404-CYG ------------------------------------------------------------------------------------------------------------------------------------