8284( 11) - 04/06/00 11:34 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8284 Version: 11 Check-in Date: 06-Apr-2000 11:32:41 1.Proposal Title: Deep STIS Observations of BALQSO PG 0946+301 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Kirk Korista Western Michigan University CoI: Dr. Wil van Breugel IGPP, LLNL N CoI: Prof Norman Murray Canadian Institute for Theoretical N Astrophysics, University of Toronto CoI: Dr Bev Wills University of Texas N CoI: Dr. Patrick Ogle Massachusetts Institute of Technology N CoI: Dr. Sally Laurent-Muehleisen Lawrence Livermore National Lab N CoI: Dr. Smita Mathur Smithsonian Institution Astrophysical N Observatory CoI: Dr. Max Pettini Institute of Astronomy, Cambridge N CoI: Dr. Michael Brotherton Lawrence Livermore N CoI: Prof. Bob Becker UC Davis N CoI: Dr. Michael Crenshaw Catholic University of America Y CoI: Dr. Nahum Arav Univ. of California, Berkeley N CoI: Dr. Marthijn de Kool Astrophysical Theory Centre, Australian N National University CoI: Dr. Vesa Junkkarinen University of California, San Diego N CoI: Dr. Ari Laor Technion N CoI: Prof Marshall Cohen California Institute of Technology N CoI: Dr. Paul Green Smithsonian Astrophysical Observatory N CoI: Dr. Anuradha Koratkar Space Telescope Science Institute N CoI: Dr. Craig Foltz MMT Observatory N CoI: Prof. William Brandt Penn State N 8284( 11) - 04/06/00 11:34 - [ 2] ------------------------------------------------------------------------------------ 5. Abstract A major goal in the study of AGN outflows is the determination of the ionization equilibrium and abundances (IEA) in broad absorption line (BAL) QSOs. In the last few years it has become clear that partial coverage of the continuum source and saturation are common in BALs, and these frustrate attempts to determine the IEA from available HST data because of limitations imposed by the S/N ratio and spectral coverage. We therefore propose to reobserve the most suitable BAL IEA target: PG 0946+301. These observations will allow us to measure saturation using at least six different diagnostics, and therefore derive real column densities. The wide UV spectral coverage will enable us to measure several occurrences of BALs from different ions of the same element which are the key to determining the IEA of the flow. In addition, the combined STIS/FOS data will yield the first possibility of detecting BAL variability in the rest-frame far UV, and the data on the highest ionizatio n BALs will shed light on the connection between the BAL and warm absorber phenomena. This proposal is a crucial part of a multiwavelength campaign on PG 0946+301 which also includes ASCA, FUSE and ground-based observations. Taken together, we believe these data will revolutionize our understanding of quasar outflows. ------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 3] Observations Description ------------------------ Achieving our scientific objectives necessitates gathering very high S/N spectroscopic data for the 500--1600 Angstrom\ rest frame band of a specifically well-suited BALQSO. Furthermore, to maximize the return from all of the BAL- diagnostics we need roughly similar S/N (50--100) and spectral resolution across the spectrum. PG 0946+301 is ideally suited for STIS observations. The needed rest-frame spectral coverage coincides well with the observational capabilities of the instrument. From the existing data we know that the low resolution gratings with their higher throughput will suffice to realize our goals since all the important features in the observed BALs are \gtorder 500 km. We plan to observe PG 0946+301 for 10 orbits with the G230L grating and 30 orbits with the G140L grating. This division of observing time should yield similar S/N across the whole HST-UV band. Figure 2 illustrates that the G230L observations will triple the existing S/N across the whole band, t hu s allowing for a significant improvement in the analyses of the BALs lying in the rest frame 710 Angstrom-- 1430 Angstrom. A far greater improvement is expected from the G140L grating; there the S/N will increase by factors of 4-- 22 with four times higher spectral resolution, enabling us to extract detailed information from the eight important BALs in this spectral region (see Fig. 2); this is unquestionably infeasible with the archival FOS G160L spectra. The S/N levels in Figure 2 are easily obtainable with the STIS FUV and NUV MAMA detectors (Kaiser, et al. 1998). Due to instrumental considerations, the STIS observations must be spread over several days. We do not expect to detect variability in the BALs on this time scale. However, such a detection will have profound implications on our inferences for the number density in the flow and its distance from the central source. The request for a total of 40 orbits is based on our extensive work with the available data of bo th PG 0946+301 and other BALQSOs, and on simulations which sh ow the feasibility of obtaining our goal given the requested observing time. Exposure times were calculated with the STIS Cycle 8 Exposure Time Calculator on the World Wide Web, using the required S/N, previous HST spectra, and the 0.2x0.2 aperture as inputs. The instrument-related issues of the observations and the data reduction will be handled by Mike Crenshaw (GSFC) who is a member of the STIS team. Real Time Justification ----------------------- None ASCA: X-ray data give us the only direct information about the shape of the ionizing continuum beyond ~ 30 eV, which is vital for constraining the ionization equilibrium. Unlike optical/UV data, the absorption seen in the X- ray data is mainly due to bound-free opacity, whereas the optical/UV absorption data is due to bound-bound opacity (i.e., lines). Therefore, X-ray data yield diagnostics which are much less sensitive to saturation effects. We have an approved program for a 100 ksec ASCA observation of PG 0946+301 (PI Paul Green). item FUSE (Far Ultraviolet Spectroscopic Explorer): Within the spectral coverage of FUSE (400--530Angstrom\ in the object's rest-frame) we expect to find BALs that can serve as unique saturation diagnostics (Si IV Lambda458 and N III Lambda452), which combined with HST data will enable us to determine saturation levels up to fifty times the apparent optical depth; BALs from very high- ionization states (Si XII and S XIV) and BALs from five i ons of neon. The FUSE PI-team allocated 25 ksec to observe PG 0946+301 and will coordinate it to coincide with the STIS observation. item Optical: In the optical regime it is important to obtain a very high S/N data of the C IV Lambda1549 BAL (which is the only one observable from the ground) with a high spectral resolution. From this spectrum an accurate optical depth template can be extracted and compared with all the UV BALs in order to find ionization differences across the troughs. Bob Becker (UC Davis) has agreed to propose these (Keck) observations concurrent with the space-based observations. It is also beneficial to obtain spectropolarimetry from the ground. The polarized light spectrum give us information about another photon trajectory through the BAL region, thus yielding valuable information about the geometry of the absorbing gas. Marshall Cohen (Caltech) has agreed to obtain Keck spectropolarimetry observations. Currently both high and low-resolution spect ro scopy with the Keck telescope do not extend far enough into the blue to cover the C IV BAL in PG 0946+301. However, both instruments are expected to have full blue side capability before the HST observations will be taken. endenumerate Calibration Justification ------------------------- Additional Comments ------------------- FUSE and ground-based observations will be scheduled to coincide with the HST observations. ------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 4] Data Distribution Paper Products: Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 5] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PG0946+301 GALAXY, QSO RA=9H 49M 41.1S +/- 0.05S, J2000 Z = V = 16.2 DEC=29D 55' 18.8" +/- 0.5" 1.216 8284( 11) - 04/06/00 11:34 - [ 6] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 14-Feb-2000 AND 27-Feb-2000 SCHED 100% 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 7] Visit: 02 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 8] Visit: 03 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 9] Visit: 04 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 10] Visit: 05 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 17-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/F ACCUM 52X0.2 G140L 1425 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 11] Visit: 06 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/C ACCUM 52X0.2 G430M 3305 CR-SPLIT=2 1 35 M CD ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/C ACCUM 52X0.2 G430M 3305 CR-SPLIT=2 1 42 M CD ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/C ACCUM 52X0.2 G430M 3305 CR-SPLIT=2 1 42 M CD ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/C ACCUM 52X0.2 G430M 3165 CR-SPLIT=2 1 43 M CD ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/C ACCUM 52X0.2 G430M 3165 CR-SPLIT=2 1 43 M CD ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 12] Visit: 07 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 13] Visit: 08 Visit Priority: Visit Requirements: SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 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 PG0946+301 STIS/C ACQ F28X50L MIRROR 1 3.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 36 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0, 0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0,-0.3 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 PG0946+301 STIS/N ACCUM 52X0.2 G230L 2376 1 45 M POS TARG 0.0,-0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8284( 11) - 04/06/00 11:34 - [ 14] Summary Form for Proposal 8284 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 14-Feb-2000 AND 27-Feb-2000 SCHED 100% POS TARG 0.0, 0.3 POS TARG 0.0, 0.6 POS TARG 0.0,-0.3 POS TARG 0.0,-0.6 SCHED 100% BETWEEN 20-Mar-2000 AND 05-May-2000 SCHED 100% BETWEEN 20-Mar-2000 AND 17-May-2000 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140L G430M G230L ------------------------------------------------------------------------------------------------------------------------------------ Target Names PG0946+301 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 3305 3165 2376 ------------------------------------------------------------------------------------------------------------------------------------