6548( 8) - 12/04/96 14:25 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6548 Version: 8 Check-in Date: 04-Dec-1996 14:21:45 1.Proposal Title: The Cool Interstellar Medium in Hot Clusters of Galaxies ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle GALAXIES & CLUSTERS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: JOEL BREGMAN UNIVERSITY OF MICHIGAN CoI: Patricia Knezek Observatories of the Carnegie Institution N of Washington ------------------------------------------------------------------------------------ 6. Abstract Three important phenomena can produce cool absorbing gas in rich clusters of galaxies: stripping of galactic gas by the hot ambient medium; infall of cool gas into the cluster; and the radiative cooling of the hot gas in the cluster core (cooling flows). Fortunately, each mechanism has a distinctive signature through its spatial distribution and metallicity. We propose FOS observations to detect UV resonance absorption lines against QSOs that are projected behind rich clusters whose hot gas properties are well- studied. These lines of sight range from the inner to the outer parts of both cooling flow and non-cooling flow clusters. These observations will be powerful diagnostics in understanding cool gas production mechanisms and in characterizing the absorbing properties of clusters, which will be valuable for understanding quasar absorption statistics. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to obtain single spectra for each object with the G270H plus Red Digicon on the FOS with the 0sec point9 aperture. The G270H observation (2230 - 3270 Angstrom) covers the ionMg2 doublet near 2798 Angstrom as well as a series of ionFe2 lines, and our goal is to obtain a signal-to -noise of at least 30 per diode at the ionMg2 doublet. For S/N = 30 in 2 Angstrom diodes, an equivalent width of 1 Angstrom will be a 15 Sigma detection, so even a 0.2 Angstrom equivalent width will be a 3 Sigma detection. The ionMg2 doublet is often measured to have equivalent widths of 0.2-2 Angstrom in quasar absorption line systems, so if these clusters are responsible for some of these systems, they will be detected. From first principles, the stronger ionMg2 line reaches an optical depth of unity for N(HI) = 7.6 x10^17 ( b/50 km s^-1) H/Mg cm^-2, when it would have an equivalent width of 0.6 ( b/50 kms)Angstrom. From our estimates (above), we expect a column of this value or greater, so an equivalent width of 0.2-2 Angstrom is a sensible expectation. The series of ionFe2 lines have lower opacity, so if the ionMg2 lines are saturated (as can be determined from their ratio), the ionFe2 lines will be an aid to determining the column of material and its metallicity (at least some of these lines are likely to be detected with equivalent widths >~ 0.2 Angstrom) The flux densities at the redshifted positions of the ionMg2 doublet are not known from direct observation, but we have estimated them by using a template spectrum for the optical-ultraviolet region (McDowell 1994) and the Galactic extinction. These sources may be a bit brighter in the UV than McDowell's mean AGN spectrum because they are X-ray bight objects. As an example, for the AGN projected behind Abell 119 (a flux density of 7.95 x10^-17 erg cm^-2 s^-1 AA^-1 at 5500 Angstrom; Table 2), the flux density at the ionMg2 doublet (2924 Angstrom) is 2.75 x10^-16 erg cm^-2 s^-1 AA^-1 (differential absorption is included in this calculation). After accounting for guide star acquisition, Binary Search acquisition, and instrumental overheads, three orbits will result in an effective exposure time of 121 minutes and a S/N = 31.6. Similar calculations were performed for each target to determine the observing times in this program; acquisition of all targets will take place with the Binary Search on the FOS. The S/N will be close to or above 30 for all but the first target, which will have S/N = 24.1. Real Time Justification ----------------------- None. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO0020+287 GALAXY,QSO RA=00H 20M 38.01S +/- J2000 V = 19.3+/-0.7 1.0",DEC=28D 42' 30.80" +/- 1",PLATE-ID=01H5 Comments: The RA/DEC from the DSS differs from that measured on the POSS with a measuring engine, so we wish to remeasure the location of the object. If possible, this should be scheduled in the latter half of the year (after July), which will permit us to determine updated magnitudes. NOTE: Coords updated as per PI. - RAL - 9 April, 1996. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1982.8 0.0 0.0 0.0 2 QSO0056-010 GALAXY,QSO RA=00H 56M 7.08S +/- 0.7",DEC=- J2000 V = 19.0+/-0.7 1D 03' 40.09" +/- 0.7",PLATE- ID=023A Comments: If convenient, schedule after July so that updated magnitudes can be obtained. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1982.55 0.0 0.0 0.0 3 QSO0107-156 GALAXY,QSO RA=1H 09M 31.55S +/- 0.8",DEC=- J2000 V = 18.2+/-0.6 15D 21' 51.6" +/- 0.8",PLATE- ID=03Y7 Comments: If convenient, schedule after July so that updated magnitudes can be obtained. NOTE: There were no magnitude updates given by the time this target had to be flight ready so the original values stand. - RAL - 6/24/96 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1983.70 0.0 0.0 0.0 4 QSO0909-095 GALAXY,QSO RA=9H 9M 30.74S +/- 0.7",DEC=-9D J2000 V = 18.31+/-0.7 32' 24.23" +/- 0.7",PLATE- ID=01MM Comments: Flux updated as per PI. - RAL - 9 April, 1996. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1982.08 0.0 0.0 0.0 5 QSO1127+269 GALAXY,QSO RA=11H 27M 36.39S +/- J2000 V = 16.75+/-0.8 1.0",DEC=26D 54' 50.33" +/- 1.0",PLATE-ID=019K Comments: Flux updated as per PI. - RAL - 9 April, 1996. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1984.17 0.0 0.0 0.0 6 QSO1348+263 GALAXY,QSO RA=13H 48M 48.30S +/- J2000 V = 18.00+/-0.8 1.2",DEC=26D 22' 20.2" +/- 1.2",PLATE-ID=019J Comments: Flux updated as per PI. - RAL - 9 April, 1996. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J1982.39 0.0 0.0 0.0 6548( 8) - 12/04/96 14:25 - [ 2] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 7 QSO0909-095- GALAXY,QSO RA=9H 9M 30.74S +/- 0.7",DEC=-9D J2000 V = 18.31+/-0.7 HOPR 32' 24.23" +/- 0.7",PLATE- ID=01MM Comments: Flux updated as per PI. - RAL - 9 April, 1996. Epoch info dropped for HOPR repeat as it was always unnecessary and was now causing errors with new s/w. The epoch info is implicitly accounted for by the GS Plate ID. This target was added for purposes of the HOPR repeat since using the original one ( which did not otherwise need to be changed ) with the Epoch was causing errors and because the system does not allow changes to targets that have already been observed. This target is otherwise the same target as the original Target 4, QSO0909-095. 6548( 8) - 12/04/96 14:25 - [ 3] 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 QSO0020+287 FOS/RD ACQ/BIN 4.3 MIRROR 1 148 S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO0020+287 FOS/RD ACCUM 1.0 G270H 1 8750 S ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 4] 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 QSO0056-010 FOS/RD ACQ/BIN 4.3 MIRROR 1 110 S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO0056-010 FOS/RD ACCUM 1.0 G270H 1 6300 S ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 5] Visit: 03 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 QSO0107-156 FOS/RD ACQ/BIN 4.3 MIRROR 1 53 S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO0107-156 FOS/RD ACCUM 1.0 G270H 1 3950 S ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 6] Visit: 04 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 QSO0909-095 FOS/RD ACQ/BIN 4.3 MIRROR 1 100 S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO0909-095 FOS/RD ACCUM 1.0 G270H 1 8730 S ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 7] Visit: 05 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 QSO1127+269 FOS/RD ACQ/BIN 4.3 MIRROR 1 18 S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO1127+269 FOS/RD ACCUM 1.0 G270H 1 4030 S ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 8] Visit: 06 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 QSO1348+263 FOS/RD ACQ/BIN 4.3 MIRROR 1 84 S ONBOARD ACQ FOR 20 ARY ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO1348+263 FOS/RD ACCUM 1.0 G270H 1 6390 S ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 9] Visit: 54 Visit Requirements: On Hold Comments: Additional Comments: HOPR Repeat for Visit 04 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 QSO0909-095 FOS/RD ACQ/BIN 4.3 MIRROR 1 100 S ONBOARD ACQ FOR 20 -HOPR ARY Comments: HOPR Repeat ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO0909-095 FOS/RD ACCUM 1.0 G270H 1 8730 S -HOPR Comments: HOPR Repeat ------------------------------------------------------------------------------------------------------------------------------------ 6548( 8) - 12/04/96 14:25 - [ 10] Summary Form for Proposal 6548 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/BINARY ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 20 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G270H ------------------------------------------------------------------------------------------------------------------------------------ Target Names QSO0020+287 QSO0056-010 QSO0107-156 QSO0909-095 QSO1127+269 QSO1348+263 QSO0909-095-HOPR ------------------------------------------------------------------------------------------------------------------------------------