7358( 5) - 11/06/98 14:53 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7358 Version: 5 Check-in Date: 06-Nov-1998 14:52:57 1.Proposal Title: The Unusual Absorption Line System of PG 2302+029 -- Ejected or Intervening? ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Buell T. Jannuzi National Optical Astronomy Observatories CoI: John Bahcall Institute for Advanced Study N CoI: A. Boksenberg Institute of Astronomy, University of N Cambridge CoI: Fred Hamann University of California, San Diego N CoI: George Hartig Space Telescope Science Institute N CoI: Sofia Kirhakos Institute for Advanced Study N CoI: W. L. W. Sargent California Institute of Technology N CoI: D. P. Schneider The Pennsylvania State University N CoI: D. A. Turnshek University of Pittsburgh N CoI: Ray Weymann The Observatories of the Carnegie N Institution of Washington ------------------------------------------------------------------------------------ 5. Abstract A high-ionization broad absorption line system (C IV, N V, and O VI doublets; FWHM 3, 000 to 5, 000 km s^-1; z_rmabs=0.7) in the HST FOS UV spectrum of PG 2302+029 (z=1.052) has unprecedented properties. A distinct narrow line system (FWHM <250 km s^-1, z_abs=0.702) is also resolved within the broad system. If produced by material intrinsic to the quasar then the absorbing gas has been ejected from the quasar at more than sim56, 000 km s^-1. This extremely large ejection velocity as well as its ``detached'' nature (the reddest extent of the broad line absorption is more than 50, 000 km s^-1 from the quasar rest frame) would be unlike any known intrinsic absorber in QSOs. Alternatively, the broad and narrow systems could be produced by gas in a foreground cluster or super-cluster of galaxies. However, previous examples of such absorption have always included absorption by low-ionization species (e.g. Mg II, Si II), which are not detected in the PG 2302+029 systems. We will undertake STIS and WFPC2 observations designed to help to identify the cause of this absorption system and allow us to determine whether the system is an extreme example of previously known classes of quasar absorption lines or represents an entirely new phenomenon. ------------------------------------------------------------------------------------ 7358( 5) - 11/06/98 14:53 - [ 2] Observations Description ------------------------ Some basic source characteristics for PG 2302+029: z=1.052; redshift of the broad absorption system z=0.7; observed flux, at 1300 Angstrom 5-7times10^-15 ergs s^-1 cm^-2 AA^-1 (based on IUE data), at 1800 Angstrom 4times10^-15 ergs s^-1 cm^-2 AA^-1 (based on HST data), at 2400 Angstrom 4times10^- 15 ergs s^-1 cm^-2 AA^-1 (based on HST data); source visible for 52 minutes each orbit. We have planned the following observations for our 5 orbit allocation: 1.) We wish to investigate if the broad system is comprised of multiple narrow systems. Given our limited time, only one orbit could be spare for observations using the near-UV MAMA, E230M grating, and 0.2x0.2'' aperture which will provide coverage at the necessary wavelengths and spectral resolution (R=30, 000, 10 km s^-1), in not quite the s/n we would have liked. Given our time constraints, we have chosen not to include the O VI region of the absorption system. We will observe using a grating tilt of 2415 Angstroms. 2.) We wish to look for broad absorption caused by by other atomic species and ionization states that might be part of the z=0.7 system. We will search for features similar to those observed for C IV, N V, and O VI that might be produced by C II (903.7, 904.0), C III (977.0), N II (915.6), N III (685.0, 685.5, 763.3), N IV (765.1), Ne VIII (770.4, 780.3), O III (702.3), O III (832.9), O IV (787.7), P IV (950.7), S VI (933.4, 944.5), and S V (786.5). All of these species have successfully been observed in a few well-measured BAL and/or associated absorption systems. Ne VIII is of particular interest because it can provide an upper limit to the ionization of the gas. All of these species would have observed wavelengths between 1150 and 1700 Angstrom and would be expected to have velocity widths comparable to those of the C IV, N V, and O VI features (3, 000 to 5, 000 km s^ -1). A spectrum of modest spectral resolution, but good signal-to- noise ratio covering the above wavelength region can be produced by observing with the FAR- UV MAMA, G140L grating, and 52x0.2'' slit. This will yield a spectrum from 1150 -1730 Angstrom at a spectral resolution of 300 km s^-1. One orbit with this set -up provides enough exposure time to yield a S/N of over 15 at 1300 angstroms. 3.) In order to search for variability in the CIV, NV, and OVI features when compared to our existing FOS spectrum, we will observe using the G230LB and CCD detector. The G230LB grating provides a spectral resolution of 600 km s^-1. Two orbits will provide S/N>30 from 2100 to 3000 Angstrom, allowing us to detect changes in the N V and C IV broad absorption when we compare these observations to our existing FOS spectra. The O VI region will also be included in this observation, but observed at lower S/N. 4.) We will use the WFPC2 to search for any galaxies extremely close to the line of sight that might be related to a supernovae or other object that might be producing the observed absorption. We would like to use dithering and take appropriate multiple exposures to improve our ability to do PSF subtraction. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7358( 5) - 11/06/98 14:53 - [ 3] Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7358( 5) - 11/06/98 14:53 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PG2302+029 EXT-MEDIUM, ABSORPTION RA=23H 4M 45S +/- 1.0", DEC=03D J2000 Z = F-CONT(2600.)=5.+/-0.1e-15 LINE SYSTEM - 11' 46" +/- 1.0", PLATE-ID=0514 1.052 F-CONT(1600.)=3.8+/-0.2e-15 EXTRAGALACTIC, GALAXY, V = 15.77+/-0.3 QSO 7358( 5) - 11/06/98 14:53 - [ 5] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 PG2302+029 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 1 S ONBOARD ACQ FOR 20 CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 PG2302+029 STIS/C ACQ/PEA 0.2X0.2 MIRROR 1 2 S ONBOARD ACQ FOR 30 CD K ------------------------------------------------------------------------------------------------------------------------------------ 30 PG2302+029 STIS/N ACCUM 0.2X0.2 E230M 2415 1 950 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 PG2302+029 STIS/N ACCUM 0.2X0.2 E230M 2415 1 950 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 PG2302+029 STIS/C ACQ/PEA 52X0.2 MIRROR 1 2 S ONBOARD ACQ FOR 60 SAVE CD K OFFSET PG2302 Comments: Peak up into the slit in preparation for the G140L observations. ------------------------------------------------------------------------------------------------------------------------------------ 60 PG2302+029 STIS/F ACCUM 52X0.2 G140L 1425 1 1100 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 70 PG2302+029 STIS/F ACCUM 52X0.2 G140L 1425 1 1100 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 7358( 5) - 11/06/98 14:53 - [ 6] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 PG2302+029 STIS/C ACCUM 52X0.2 G230LB 2375 CR-SPLIT=NO 1 1160 S USE OFFSET PG2302 CD ------------------------------------------------------------------------------------------------------------------------------------ 20 PG2302+029 STIS/C ACCUM 52X0.2 G230LB 2375 CR-SPLIT=NO 1 1160 S POS TARG 0.0, 0.2 USE CD OFFSET PG2302 ------------------------------------------------------------------------------------------------------------------------------------ 50 PG2302+029 STIS/C ACCUM 52X0.2 G230LB 2375 CR-SPLIT=NO 1 1410 S POS TARG 0.0, 0.4 USE CD OFFSET PG2302 ------------------------------------------------------------------------------------------------------------------------------------ 60 PG2302+029 STIS/C ACCUM 52X0.2 G230LB 2375 CR-SPLIT=NO 1 1410 S POS TARG 0.0, 0.6 USE CD OFFSET PG2302 ------------------------------------------------------------------------------------------------------------------------------------ 7358( 5) - 11/06/98 14:53 - [ 7] Visit: 03 Visit Priority: Visit Requirements: GROUP 02, 03 WITHIN 14 D 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 ------------------------------------------------------------------------------------------------------------------------------------ 90 PG2302+029 WFPC2 IMAGE WF2-FIX F814W CR-SPLIT=DEF 4 510 S ------------------------------------------------------------------------------------------------------------------------------------ 7358( 5) - 11/06/98 14:53 - [ 8] Summary Form for Proposal 7358 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 52X0.2 WF2-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA STIS/FUV-MAMA WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CR-SPLIT=NO CR-SPLIT=DEF ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 20 ONBOARD ACQ FOR 30 ONBOARD ACQ FOR 60 SAVE OFFSET PG2302 USE OFFSET PG2302 POS TARG 0.0, 0.2 USE OFFSET PG2302 POS TARG 0.0, 0.4 USE OFFSET PG2302 POS TARG 0.0, 0.6 USE OFFSET PG2302 GROUP 02, 03 WITHIN 14 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E230M G140L G230LB F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names PG2302+029 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 2415 1425 2375 ------------------------------------------------------------------------------------------------------------------------------------