5928( 4) - 08/02/95 13:20 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5928 Version: 4 Check-in Date: ********** 1.Proposal Title: Hidden QSOs in ``Warm'' Infrared Ultraluminous Galactic Nuclei ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Dean C. Hines Steward Observatory CoI: Dr. Beverley Wills University of Texas N CoI: Dr. Robert Goodrich StScI N CoI: Dr. Paul Smith Steward Observatory N CoI: Dr. Richard Allen Steward Observatory N CoI: Dr. Michael Sitko University of Cincinnati N ------------------------------------------------------------------------------------ 6. Abstract Our ground-based optical spectropolarimetry shows that nearly half of our sample of ``warm'' IR-Ultraluminous AGNs (L_IR >= 10^11.5 Lsun) exhibit high and wavelength dependent polarization (up to p = 25%). In several we observe typical QSO broad emission line spectra in polarized light suggesting an inner structure similar to the axisymmetric geometry proposed for lower luminosity AGNs such as NGC 1068. Our ground based spectropolarimetry also suggests a strong connection between the IR- Ultraluminous AGNs and the rare Broad Absorption Line (BAL) QSOs; the BALQSOs and the IR-Ultraluminous AGNs would appear as normal UV-excess QSOs if viewed along a different line of sight. UV-spectropolarimetry, which can only be accomplished with the HST FOS, combined with our ground-based optical spectropolarimetry will allow us to distinguish between electron scattering, dust scattering and dichroic absorption. In addition, the wide wavelength coverage will allow us to compare the polarization properties of the continuum, and emission-line and absorption-line features of different ionizations, and thus constraining the geometries of these regions. ------------------------------------------------------------------------------------ 5928( 4) - 08/02/95 13:20 - [ 2] Observations Description ------------------------ We propose to obtain UV spectropolarimetry of 2 highly polarized IR- Ultraluminous AGNs using the HST FOS. One is very highly polarized and probably highly obscured, while the other is confirmed BALQSOs. We have chosen the G270H grating for the polarization observations because it offers the best throughput. We also include G190H to examine the detailed emission/absorption profile of CIV in IRAS 07598+6508, and we include G190H observations to look for possible CIV and SiIV Broad Absorption Lines in IRAS 14026+4341 in total light. The expected UV polarizations for IRAS 07598+6508 and IRAS 14026+4341 are 4% and 12% respectively. Accurate polarimetry requires p/dp >= 5 in each resolution element, where dp = sqrt(2/Ct) with (C) being the expected counts per second per diode, and (t) the total integration time. We estimate C using the prescriptions outlined in the FOS Users Manual (Version 5.0) assuming F \propto nu^-2 in Table 1.2.2 and scaling by the object's V magnitude, or (when available) by estimating the count rate from highly smoothed IUE spectra. The steep powerlaw is justified by the reddened spectrum observed for these objects. We have selected bin sizes large enough to maximize the signal-to- noise, but small enough that the emission and absorption line polarization can be accurately determined. To obtain the polarization, at least 4 separate exposures with the waveplate at different position angles are required. The total number of orbits required for each object was estimated from the total integration time plus the overhead times needed to acquire the object, and to obtain 4 exposures per polarization observation. The overhead times for POLSCAN-4B were provided by USB and add about 6 minutes to the nominal overhead for ACCUM. For example, we estimate the count rate for the MgII broad absorption trough in IRAS 07598+6508 to be 0.5 c/s using the G270H filter and assuming a polarization at least 4%. The absorption feature is 12,000 km s-1 wide so 10 pixel bins allows approximately 5 resolution elements across the feature. The required exposure time to achieve p/dp >= 5 is 1.8 hours. For 3 orbits, the overhead times are 30 min, 27 min, and 14 min for guide star, acquisition and POLSCAN+ACCUM respectively for a total 71 minutes. The total spacecraft time is thus 179 minutes. Each orbit lasts approximately 60 minutes, so 3 orbits are needed to accomplish this observation. Observations of polarized and null standards during Cycle 4 have been planned by the FOS/Spectropolarimetry team (R.A. & P.S.). These time estimates are accurately reflected in the RPS2 output. 2 August, 1995 NOTE: Due to problems with the calibration of FOS/RD polarimetry, we have now switched to FOS/BL, with concurrent changes in the ACQ/BINARY exposure times. The new FOS/BL ACQ/BINARY exposure times we are using are ones which were recommended by the FOS Instrument Scientist. Real Time Justification ----------------------- We do not require REAL-TIME observations. Calibration Justification ------------------------- Additional Comments ------------------- Ground-based optical spectropolarimetry of all our targets has been previously obtained (resolution 300 -- 750 kms). Additional higher resolution optical spectropolarimetry of IRAS 07598+6508 and IRAS 14026+4341 are planned for the Spring and Summer 1995 seasons using facilities at McDonald and Steward Observatories. ------------------------------------------------------------------------------------ 5928( 4) - 08/02/95 13:20 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5928( 4) - 08/02/95 13:20 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 IR1334+24 GALAXY, QSO, RA = 13H 37M 18.718S +/- 0.05S, J2000 Z = V = 14.7 +/- 0.5 Ultraluminous IR Gal, DEC = 24D 23' 02.95" +/- 0.4", 0.1078 F(3100) = 5 E-15 Nucleus, BLR PLATE-ID = 01GF F(2700) = 4 E-15 F(1900) = 2 E-15 E(B-V) = 0.0 Comments: Fluxes based on low S/N IUE spectrophotometry 2 IR1402+43 GALAXY, QSO, RA = 14H 04M 38.860S +/- 0.05S, J2000 Z = V = 15.7 +/- 0.5 Ultraluminous IR Gal, DEC = 43D 27' 07.0" +/- 0.4", 0.323 B-V = 0.2 Nucleus, BLR PLATE-ID = 00XZ F(3200) = 3 E-15 Comments: Flux density based on ground-based spectrophotometry 5928( 4) - 08/02/95 13:20 - [ 5] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 100 IR1334+24 FOS/BL ACQ/BIN 4.3 MIRROR 1 6.5S ONBOARD ACQuisition FOR 101-102 ARY ------------------------------------------------------------------------------------------------------------------------------------ 101 IR1334+24 FOS/BL ACCUM 1.0 G190H 1959 1 1800S ------------------------------------------------------------------------------------------------------------------------------------ 102 IR1334+24 FOS/BL ACCUM 1.0 G270H 2750 POLSCAN = 4B 3 2080S ------------------------------------------------------------------------------------------------------------------------------------ 5928( 4) - 08/02/95 13:20 - [ 6] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 200 IR1402+43 FOS/BL ACQ/BIN 4.3 MIRROR 1 16S ONBOARD ACQuisition FOR 201-202 ARY ------------------------------------------------------------------------------------------------------------------------------------ 201 IR1402+43 FOS/BL ACCUM 1.0 G270H 2750 POLSCAN=4B 1 1200S ------------------------------------------------------------------------------------------------------------------------------------ 202 IR1402+43 FOS/BL ACCUM 1.0 G270H 2750 POLSCAN = 4B 5 2230S ------------------------------------------------------------------------------------------------------------------------------------ 5928( 4) - 08/02/95 13:20 - [ 7] Summary Form for Proposal 5928 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/BINARY ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters POLSCAN = 4B POLSCAN=4B ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQuisition FOR 101-102 ONBOARD ACQuisition FOR 201-202 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G190H G270H ------------------------------------------------------------------------------------------------------------------------------------ Target Names IR1334+24 IR1402+43 ------------------------------------------------------------------------------------------------------------------------------------