7393( 7) - 03/11/98 10:10 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7393 Version: 7 Check-in Date: 11-Mar-1998 10:09:45 1.Proposal Title: Black Hole A0620-00 and Advection-Dominated Accretion ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: JEFFREY MCCLINTOCK CFA CoI: Ronald Remillard Massachusetts Institute of Technology N ------------------------------------------------------------------------------------ 5. Abstract Six X-ray novae (aka soft X-ray transients) provide the most clear-cut evidence presently available for the existence of black holes. We propose STIS spectral observations of the prototype object A0620-00 in its quiescent state. In Cycle 1, we observed A0620-00 with the FOS blue detector; however, the observations were very seriously compromised by the limited capability of the FOS combined with the unexpected faintess of the source. We now propose to revisit A0620-00 in the post- COSTAR era for two reasons: (1) to obtain a greatly improved UV spectrum using the STIS with its 2-D detectors, and (2) to test the new advection-dominated accretion flow (ADAF) model for accretion onto black holes. The result of fitting the ADAF model to the current broadband spectrum (optical to X- ray) of A0620-00 is important because it can be construed as a ``proof" that the compact object is a true black hole with an event horizon. At present the broadband spectrum of A0620-00 is admirably fitted by the ADAF model. However, the UV portion of the spectrum is very weakly constrained, and we propose to tighten the constraints substantially. ------------------------------------------------------------------------------------ 7393( 7) - 03/11/98 10:10 - [ 2] Observations Description ------------------------ We require a series of identical spectra extending as far shortward into the UV as possible. We will use exclusively the following grating/detector/slit combination: G230L/NUV-MAMA/52x0.5. The observations will consist of a series of 10-minutes exposures in the ACCUM mode. We will make two visits to A0620-00 (V616Mon), which is the prime target. The duration of the first and second visits will be five and three spacecraft orbits, respectively. In addition, we will make one one-orbit visit to Cen X-4 (V822Cen). Both A0620-00 and Cen X-4 are point sources. Real Time Justification ----------------------- No real-time observations are requested. We do require, however, that the five spacecraft orbits during visit 1 be contiguous; similarly, the three spacecraft orbits during visit 2 must also be contiguous. Calibration Justification ------------------------- We request no special calibrations for our program. Additional Comments ------------------- We request that the PI be notified ASAP after these HST/STIS observations have been scheduled so that he can arrange for contemporaneous ground-based observations. ------------------------------------------------------------------------------------ Data Distribution Media: DAT Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7393( 7) - 03/11/98 10:10 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V616MON STAR,X-RAY NOVAE RA=06H 22M 44.51S +/- 1.0",DEC=- J2000 V = 18.3+/-0.3 00D 20' 45.0" +/- 1.0",PLATE- B-V = 1.35+/-0.20 ID=00TV E(B-V) = 0.35+/-0.03 Comments: Flux Data: There is an additional UV spectral component that can be modeled as a 9000K blackbody with F{lambda}@4000A = 7e-17 ergs/cm^2-s-A. 2 V822CEN STAR,X-RAY NOVAE RA=14H 58M 21.95S +/- 1.0",DEC=- J2000 V = 18.5+/-0.3 31D 40' 5.9" +/- 1.0",PLATE- B-V = 0.8+/-0.2 ID=02J0 E(B-V) = 0.1+/-0.05 Comments: Flux Data: The UV spectrum is relatively bright and variable and it can be modeled approximately by a 12000K blackbody with F{lambda}@3000A = 5e-17 ergs/cm^2-s-A. 7393( 7) - 03/11/98 10:10 - [ 4] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 23-Oct-1997 AND 07-Nov-1997 BETWEEN 21-Nov-1997 AND 07-Dec-1997 BETWEEN 21-Dec-1997 AND 05-Jan-1998 BETWEEN 20-Jan-1998 AND 03-Feb-1998 BETWEEN 19-Feb-1998 AND 05-Mar-1998 On Hold Comments: Additional Comments: The Special Requirements on the time of the visit (e.g. BETWEEN 23-Oct-1997 AND 07-Nov-1997) are to insure that near-simultaneous ground-based optical observations of the target will be possible--i.e. that the HST observations occur during the dark half of the lunar cycle when the sun is far from the target. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V616MON STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 10 S ONBOARD ACQ FOR 2,3,4,5,6 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2150 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 3 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 4 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 5 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 6 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7393( 7) - 03/11/98 10:10 - [ 5] Visit: 02 Visit Priority: Visit Requirements: BETWEEN 23-Oct-1997 AND 07-Nov-1997 BETWEEN 21-Nov-1997 AND 07-Dec-1997 BETWEEN 21-Dec-1997 AND 05-Jan-1998 BETWEEN 20-Jan-1998 AND 03-Feb-1998 BETWEEN 19-Feb-1998 AND 05-Mar-1998 On Hold Comments: Additional Comments: The special requirements on the time of the visit (e.g. BETWEEN 23-Oct-1997 AND 07-Nov-1997) are to insure that near-simultaneous ground-based optical observations of the target will be possible--i.e. that the HST observations occur during the dark half of the lunar cycle when the sun is far from the target. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V616MON STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 10.0 S ONBOARD ACQ FOR 2,3,4 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2150 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 3 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 4 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7393( 7) - 03/11/98 10:10 - [ 6] Visit: 03 Visit Priority: Visit Requirements: BETWEEN 19-Feb-1998 AND 05-Mar-1998 BETWEEN 21-Mar-1998 AND 03-Apr-1998 BETWEEN 19-Apr-1998 AND 03-May-1998 BETWEEN 19-May-1998 AND 02-Jun-1998 BETWEEN 17-Jun-1998 AND 01-Jul-1998 BETWEEN 16-Jul-1998 AND 31-Jul-1998 On Hold Comments: Additional Comments: The special requirements on the time of the observations (e.g. BETWEEN 19- Feb-1998 AND 05-Mar-1998) are to insure that near-simultaneous ground-based optical observations of the target will be possible--that the HST observations occur during the dark half of the lunar cycle when the sun is far from the target. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 V822CEN STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 10 S ONBOARD ACQ FOR 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 V822CEN STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2150 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7393( 7) - 03/11/98 10:10 - [ 7] Visit: 52 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 V616MON STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 10.0 S ONBOARD ACQ FOR 2,3,4 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2150 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 3 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 4 V616MON STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=6000 1 2550 S UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 7393( 7) - 03/11/98 10:10 - [ 8] Summary Form for Proposal 7393 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT BUFFER-TIME=6000 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 23-Oct-1997 AND 07-Nov-1997 BETWEEN 21-Nov-1997 AND 07-Dec-1997 BETWEEN 21-Dec-1997 AND 05-Jan-1998 BETWEEN 20-Jan-1998 AND 03-Feb-1998 BETWEEN 19-Feb-1998 AND 05-Mar-1998 ONBOARD ACQ FOR 2,3,4,5,6 ONBOARD ACQ FOR 2,3,4 BETWEEN 19-Feb-1998 AND 05-Mar-1998 BETWEEN 21-Mar-1998 AND 03-Apr-1998 BETWEEN 19-Apr-1998 AND 03-May-1998 BETWEEN 19-May-1998 AND 02-Jun-1998 BETWEEN 17-Jun-1998 AND 01-Jul-1998 BETWEEN 16-Jul-1998 AND 31-Jul-1998 ONBOARD ACQ FOR 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G230L ------------------------------------------------------------------------------------------------------------------------------------ Target Names V616MON V822CEN ------------------------------------------------------------------------------------------------------------------------------------