Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5478 Report Date: 18-Jul-95:17:29 Version: ********** Check-in Date: ********** 1.Proposal Title: TIME-RESOLVED UV AND X-RAY SPECTROMETRY OF X-RAY BINARIES CYCLE 4 MEDIUM ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID HOT STARS GO Sub Category X-RAY BINARIES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Richard A Mccray UNIVERSITY OF COLORADO USA (303)-492-7835 ------------------------------------------------------------------------------------ 7. Abstract In simultaneous observations with HST and ASCA, we will observe rapid variations in the UV and X-ray spectra of the X-ray binary Her X-1. Our purpose is to understand the accretion flow and X-ray emission. By observing UV echoes of X-ray variations (especially pulsations) on time scales down to 0.35 s, we can map the precessing accretion disk. We will use the HRS (30km/s resolution) to look for pulsations in the profile of the NV emission line at 1240 A. During these observations, we will use ASCA to find the X-ray pulse shape and spectrum, X-ray/UV phase lag, X-ray state, absorbing column, and X-ray emission lines and edges. The X-ray and UV observations will complement each other, resulting in greatly enhanced science. These observations will take place from orbital phases 0.7 to 1.0, in order to probe the geometry of the X-ray absorbing and UV fluorescing gas. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 7.20 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5478 PI: Richard A Mccray Proposal Title: TIME-RESOLVED UV AND X-RAY SPECTROMETRY OF X-RAY BINARIES CYCLE 4 MEDIUM ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Richard A Mccray 1760 USA Bram S Boroson 1760 USA Timothy Kallman 2856 USA Fumiaki Nagase 6510 JAPAN M. Ishida 6510 JAPAN Bruce Margon 3760 USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. We will observe Her X-1 during the HIGH state of the 35 day cycle with the HRS for an actual spacecraft time of 26,000 seconds, corresponding to 1.7d orbital phase 0.74 through 0.92. This observing time and orbital phase range is dictated by the desire to search for pulsations in the UV lines during the phase when optical pulsations from the disk are strongest and we have a good chance of catching a pre-eclipse "dip" in the X-ray light curve. The HRS centered at 1240 A. All observations will be taken with RAPID (0.35 second) readout mode. We decided to concentrate on this line (N V) because it is the brightest emission line in the UV spectrum and because it should be the most sensitive to X-ray illumination. During the orbital phase interval 0.7-1.0 we will coordinate simultaneous observations with the ASCA X-ray telescope. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The HST is the only telescope that can do time-resolved UV spectrometry of binary X-ray sources, the essence of this proposal. The HRS G140M velocity resolution, 20 km/s, can easily resolve the NV 1238,1242 emission lines. With our simultaneous X-ray observations, we will know the brightness, spectrum, and pulse profile and phase of the X-ray beam. With ASCA we can study the Fe K line, and compare its pulsation with the UV pulses. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The Her X-1 system orbits in 1.7 days and the X-rays vary in 35 days (attributed to shadowing by a twisted, tilted accretion disk.) We seek to observe Her X-1 when the chance to detect pulsations peaks. We are also interested in observing the eclipse ingress. Thus our plan calls for continuous observation from orbital phase 0.75 thru 0.93, and during the most favorable state of the 35 day variation. Observations are to be coordinated with the ASCA X-ray, telescope, a procedure that worked smoothly for our 1991 joint HST/Ginga observation. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Page 3 ------------------------------------------------------------------------------------ 9. Description of previous HST work. 1051-GTO/FOS-86G: MASS EXCHANGE BINARIES (B. Margon, P.I.) Observations with FOS were successful. We will use different orbital phases, RAPID readout for all exposures, and a better spectral resolution in our current proposal. P2572- GO/FOS: TIME RESOLVED UV SPECTROMETRY OF VELA X-1 This program is related to the present proposal. We did time- resolved UV spectrometry of the massive X-ray binary Vela X-1 with the FOS and simultaneous observations with the Japanese X- ray satellite GINGA. The observations took place August 19, 1991. They were successful in every sense. We obtained simultaneous X-ray and HST data. We found pulsations in the UV absorption lines and were able to measure phase shifts between the UV and X-ray pulse waveforms. This observation was the first successful demonstration of pulse phase spectroscopy of X-ray binaries. P2492- GO/HRS: CONDUCTIVE INTERFACES IN STELLAR WIND BUBBLES This program is unrelated to that of the present proposal. The observations have been executed recently and the data are now being analyzed. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). The University of Colorado operates computer facilities currently based on VAX mainframes running VMS, and SUN and DEC workstations running UNIX. For the analysis of the HST/FOS and HRS data we will use the SUN And DECstations which run IRAF and IDL in a UNIX environment. A graduate student (Mr. Bram Boroson) in the Department of Astrophysical, Planetary, and Atmospheric Sciences is currently working with the P.I. on the preparation of this proposal. If the proposed observation is successful, work based on modelling and interpreting the HST data will be a major part of Mr. Boroson's Ph.D. thesis. ------------------------------------------------------------------------------------ 11. Address Information Name: Richard A McCray Category: PI Institution: 1764 Address: Box 440 City: Boulder State: CO Zip Code: 80309 Country: USA Telephone: (303)-492-7835 Telex (or e-mail): ------------------------------------------------------------------------------------ Name: Bram S Boroson Category: CON Institution: 1760 Address: Graduate Student City: Boulder State: CO Zip Code: 80309 Country: USA Telephone: (303)-492-7805 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5478 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 HER-X-1 HZ- A,165,906 RA=16H 57M 49.81S +/- 0.01S, J2000 1 V=13.2, B-V=-0.1 HER DEC=+35D20'32.7" +/- 0.3", 2 F-CONT(1500)=5.0 +/- 2.5E-14 PLATE-ID=00CK 3 F-LINE(1550)=2.0 +/- 1.5E-13 4 F-LINE(1240)=5.0 +/- 3.5E-13 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5478 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HER-X-1 HRS ACQ 2.0 MIRROR-N21200- SEARCH-SIZE=5 1 5S 1 CYCLE 4 / 1-13 1600 BRIGHT=RETURN ONBOARD ACQ FOR 2- 13 SEQ 1-13 AT 27-AUG- 1994:09:00 +/- 1D Comments: SIMULTANEOUS OBSERVATIONS WILL BE TAKEN BY THE ASCA X-RAY TELESCOPE. NOTE PERIODS OF PRIME OBSERVING. THERE IS A SECOND PERIODICITY; WE WILL PROVIDE TIMES WHEN THIS PHASE IS FAVORABLE IN A SEPARATE DOCUMENT. ------------------------------------------------------------------------------------------------------------------------------------ 2 HER-X-1 HRS RAPID 2.0 G140L 1200- SAMPLE-TIME=0.1 1 20M 1 ZERO-PHASE 1490 JD2443805.02 +/- 0.0001D PERIOD 1.700167788D +/- .000000001D PHASE .55 +/- .1 RT ANALYSIS ------------------------------------------------------------------------------------------------------------------------------------ 3 HER-X-1 HRS RAPID 2.0 G140L 1380- SAMPLE- 1 10.4M 1 1670 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 4 HER-X-1 HRS RAPID 2.0 G140M 1240 SAMPLE- 1 39.6M 1 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 5 HER-X-1 HRS RAPID 2.0 G140M 1240 SAMPLE- 1 39.6M 1 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 6 HER-X-1 HRS RAPID 2.0 G140L 1200- SAMPLE- 1 14.4M 1 1490 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 7 HER-X-1 HRS RAPID 2.0 G140L 1380- SAMPLE- 1 14.4M 1 1670 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 8 HER-X-1 HRS RAPID 2.0 G140M 1240 SAMPLE- 1 39.6M 1 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 9 HER-X-1 HRS RAPID 2.0 G140M 1240 SAMPLE- 1 39.6M 1 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 10 HER-X-1 HRS RAPID 2.0 G140L 1200- SAMPLE- 1 14.4M 1 1490 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 11 HER-X-1 HRS RAPID 2.0 G140L 1380- SAMPLE- 1 14.4M 1 1670 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5478 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 HER-X-1 HRS RAPID 2.0 G140M 1240 SAMPLE- 1 39.6M 1 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ 13 HER-X-1 HRS RAPID 2.0 G140M 1240 SAMPLE- 1 25M 1 TIME=0.35 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5478 [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ RAPID ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE BRIGHT SAMPLE-TIME ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 7.20 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category X-RAY BINARIES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1-13; ONBOARD ACQ FOR 2-13; SEQ 1-13; AT 27-AUG-1994 09 00 +/- 1D; ZERO-PHASE JD2443805.02 +/- 0.0001D; PERIOD 1.700167788D +/- .000000001D; PHASE .55 +/- .1; RT ANALYSIS; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G140L G140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HER-X-1 HZ-HER ------------------------------------------------------------------------------------------------------------------------------------