6528( 4) - 03/06/96 08:57 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6528 Version: 4 Check-in Date: 06-Mar-1996 08:55:45 1.Proposal Title: PG 1416-129: The Only X-ray Bright BAL QSO, or the Missing Link? ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle QSO ABSORPTION LINES GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Paul J. Green Smithsonian Astrophysical Observatory CoI: Dr. Thomas Aldcroft Smithsonian Astrophysical Observatory N CoI: Dr. Smita Mathur Smithsonian Astrophysical Observatory N ------------------------------------------------------------------------------------ 6. Abstract In the last year, convincing empirical evidence has been presented that QSOs with broad absorption lines (BALs) in their UV spectra are remarkably quiet in the soft X -ray bandpass. One X-ray bright exception may exist, the QSO PG1416--129. Previous IUE UV spectra have revealed hints of BALs, but may instead be weaker, associated absorption. We propose HST (FOS) spectra of signal-to-noise (S/N) ~20 in the continuum to resolve this question. If rather than BALs, the lines are intrinsic, associated absorption, these data will also yield fresh insight into a poorly understood phenomenon in the interiors of QSOs. Recent studies have demonstrated, using both UV and X-ray data, that associated UV absorption lines and soft X-ray absorption are due to the same material. The constraints provided by combining UV and X-ray datasets is powerful for determining the physical conditions and ionization state of the absorber, determined to be low density, highly ionized, outflowing material situated outside the broad line region, similar to the BAL absorbers. The intriguing but low S/N IUE spectra suggest that PG1416--129 could prove to be a bridge between the BALQSOs and AGN with associated absorption. Fortunately, it is also bright, and extremely well-observed in the X-ray band (via ROSAT, GINGA, and ASCA). The FOS spectra we propose will thus test new unifying models for the absorbing material deep in the nucleus of QSOs. ------------------------------------------------------------------------------------ 6528( 4) - 03/06/96 08:57 - [ 2] Observations Description ------------------------ We propose to use the FOS, with the 0.5" aperture, the G130H and G190H gratings, and the blue detector, to obtain spectra of PG 1416-129 covering 1200 - 2200 Angstrom. This instrumental setup can efficiently cover the absorption lines we need for our modeling. The spectral resolution (R ~ 2000) is adequate either to measure narrow associated lines and to resolve the velocity structure of broad lines. We have used the STSDAS synphot package to calculate the predicted count rates for this source. We used 3 IUE observations (1980 through 1988), where the UV continuum flux runs from ~1.2 to 0.6 * 10^-14 ergs s^-1 cm^2 AA^-1 over the observed range LambdaLambda1400 - 2200. Note that the S/N will be substantially better near the strong emission lines of our object. The revised observation times for Phase 2 are based on an observational sequence consisting of one orbit for both acquisition and science exposure with the G190H. Because the object is non- extended, non-variable (Deltam_V < 1, Elvis et al. 1994, ApJS, 95, 1), with a well known energy distribution, we use the ACQ/BIN sequence followed by a single stage peakup. We are aware of the scattered light problem when observing at the shortest wavelengths (Ross 1994, Bartko et al. 1992). Precise post-facto corrections for this effect for PG 1416 - 129 will be possible because of the well-known energy distribution and the intrinsically blue nature of this object. The SED of this object is covered from 1000Angstrom out to 7Mum, as compiled for a study of QSO SEDs (Elvis et al. 1994). From these data, the variability in the B band is <1mag. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6528( 4) - 03/06/96 08:57 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PG1416-129 GALAXY,QSO RA=14H 19M 03.81S +/- 0.04S,DEC= B2000 Z = V = 16.10+/-0.5 -13D 10' 44.7" +/- 0.5", PLATE- 0.129 B-V = 0.32+/-0.1 ID=03YH E(B-V) = 0.14+/-0.05 F-CONT(1680)=9+/-2e-15 F-CONT(1380)=9+/-2e-15 F-LINE(1550)=1.4+/-0.3e-14 W-LINE(1550)=40+/-5 F-LINE(1903)=0.7+/-0.3e-14 W-LINE(1903)=50+/-10 6528( 4) - 03/06/96 08:57 - [ 4] Visit: 01 Visit Requirements: SCHED 50% On Hold Comments: Additional Comments: We would like to schedule this HST observation close to the time of our XTE observation of the same object (XTE Proposal number:10334, PI: Mathur) Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 PG1416-129 FOS/BL ACQ/BIN 4.3 MIRROR 1 12.1S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 PG1416-129 FOS/BL ACQ/PEA 0.3 G190H SCAN-STEP- 1 8.8S ONBOARD ACQ FOR 30 K Y=0.17,SCAN- STEP- X=0.17,SEARCH- SIZE-Y=3,SEARCH Comments: -SIZE-X=3 ------------------------------------------------------------------------------------------------------------------------------------ 30 PG1416-129 FOS/BL ACCUM 0.5 G190H 1 17M ------------------------------------------------------------------------------------------------------------------------------------ 6528( 4) - 03/06/96 08:57 - [ 5] Summary Form for Proposal 6528 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/BINARY ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=0.17 SCAN-STEP-X=0.17 SEARCH-SIZE-Y=3 SEARCH-SIZE-X=3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QSO ABSORPTION LINES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 50% ONBOARD ACQ FOR 20 ONBOARD ACQ FOR 30 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G190H ------------------------------------------------------------------------------------------------------------------------------------ Target Names PG1416-129 ------------------------------------------------------------------------------------------------------------------------------------