7760( 9) - 07/29/99 15:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7760 Version: 9 Check-in Date: 29-Jul-1999 15:15:51 1.Proposal Title: UV Spectroscopy of the Luminous Cooling Flow Nebula in A2597 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO/CAR 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Christopher Odea Space Telescope Science Institute CoI: Stefi Baum Space Telescope Science Institute N CoI: Megan Donahue Space Telescope Science Institute N CoI: Jack Gallimore Max-Planck-Institute fuer N Extraterrestrische Physik CoI: Anton Koekemoer Space Telescope Science Institute N CoI: Brian McNamara Harvard/Smithsonian Center for N Astrophysics CoI: Craig Sarazin University of Virginia N CoI: Mark Voit Space Telescope Science Institute N CoI: Mike Wise Massachusetts Institute of Technology N ------------------------------------------------------------------------------------ 5. Abstract We propose UV spectroscopy with the STIS of the emission line nebula in the luminous cooling flow cluster Abell 2597. These observations will provide the first detection of UV lines (other than Ly-alpha\ which was detected by IUE) in the spectrum of a cooling flow nebula. This will allow us to determine line ratios (or limits) on lines which are diagnostic for (1) gas cooling from the hot ICM, (2) gas in shocks, (3) gas irradiated by the EUV and soft X-rays from cooling gas, gas in mixing layers, or shocked gas, (4) gas energized by cosmic ray heating. We will determine the source of ionization for the cooling flow nebula and investigate its relationship to the ICM and the cooling flow using our groundbased optical, ISO, ROSAT, and VLA and VLBA HI observations. ------------------------------------------------------------------------------------ 7760( 9) - 07/29/99 15:16 - [ 2] Observations Description ------------------------ We propose to obtain STIS UV spectroscopy of the emission line nebula in Abell 2597. We will cover the spectrum from 1140 to 4800 Angstrom using the G140L, G230L, and G430L gratings on the blue side. We will stay on the blue side since the blue side sensitivity is sufficient for our purposes and to avoid the overhead penalty of the side switch. The G140L and G230L give us coverage of the important diagnostic UV lines from Ly-alpha through MgII2800. The G430L exposure is only a few minutes and bridges the gap between the UV and our optical ground based spectra and allows us to match the flux scales and determine accurate ratios of optical to UV lines. In order to increase thoughput in the UV (and at the cost of spectral resolution), we are using the 1.0 arcsec aperture and the G140L grating. The loss of spectral resolution is not a problem, since even at 20 Angstrom resolution the majority of the diagnostic lines are unblended. Resolution of the individual line profiles is not necessary for this project. In order to optimise the spectroscopy, the first visit will consist of three "test" grating exposures centred on the nucleus and the brightest off-nuclear lobe emission, in order to determine whether the flux is sufficient to allow spectra to be obtained at three different positions on visit 2. If not, then visit 2 will consit simply of extending the visit 1 exposures. Real Time Justification ----------------------- None. We have obtained deep optical spectra at Palomar Observatory (Figure 2). We will also use the imaging data from the cycle 6 O'Dea Etal proposal and archival F450W and F702W WFPC2 data from Trauger GTO-6228. We also plan to obtain 21cm HI observations with the VLBA to study the fine scale structure in the HI. We will combine all these data with our UV spectroscopy and ROSAT and radio continuum data to perform the definitive study of this archetypal cooling flow nebula. The currently existing radio observations (Sarazin Etal 1995) and follow on higher resolution radio observations (MERLIN) we will propose, will also provide a powerful independent constraint on the ionization of the gas. The spatial co-incidence of the radio emission with the blue lobes suggests that the radio jet has some affect on the optical appearance of the source. Our UV/optical HST line diagnostics, to be taken at three spatial locations in the source, coupled with the radio data will allow us to investigate the radio- optical continuum-emission line correlations. If shocks dominate the ionization we expect to see line ratios diagnostic of shocks where the radio jets are bright. On the other hand, in places where the radio emission is less bright, the influence of the radio source may shift to providing cosmic rays which energize the clouds - thus the emission line diagnostics may vary on and off the bright radio structure. We will look for such variations and their correlation with the radio morphology itself. We will compare the energetics of the radio lobes with the energetics required for shocks or cosmic ray ionization models, as implied by the emission-line data that we propose to obtain. We have listed A2597 as a first priority target for ISO. We will observe the fine structure lines of Si II35Mu, O I63Mu, C II158Mu and the continuum at 60, 90, 160, and 200 Mu. These data will be combined with our groundbased optical and HST UV spectroscopy to cover a wide range of diagnostic lines. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7760( 9) - 07/29/99 15:16 - [ 3] Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7760( 9) - 07/29/99 15:16 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 A2597-NUC GALAXY, Elliptical, RA=23H 25M 19.735S +/- 0.05S, J2000.0 Z=0.0821 B-V = 1.08 Radio Galaxy, CLUSTER DEC=-12D 7' 26.41" +/- 0.5", SURF(V) = 19.7 OF GALAXIES, Rich PLATE-ID=00WQ Cluster, BCM Comments: position measured from 6717 WF3 image 2 A2597-LOBE GALAXY, Elliptical, RA=23H 25M 19.835S +/- 0.05S, J2000.0 Z=0.0821 B-V = 1.08 Radio Galaxy, CLUSTER DEC=-12D 7' 23.64" +/- 0.5", SURF(V) = 19.7 OF GALAXIES, Rich PLATE-ID=00WQ Cluster, BCM Comments: position measured from 6717 WF3 image 3 A2597-KNOT GALAXY, Elliptical, RA=23H 25M 19.840S +/- 0.05S, J2000.0 Z=0.0821 B-V = 1.08 Radio Galaxy, CLUSTER DEC=-12D 7' 27.16" +/- 0.5", SURF(V) = 19.7 OF GALAXIES, Rich PLATE-ID=00WQ Cluster, BCM Comments: position measured from 6717 WF3 image 4 A2597-STAR STAR RA=23H 25M 18.328S +/- 0.05S, J2000.0 Z=0.0 V-I = 2.3 DEC=-12D 7' 48.93" +/- 0.5", V = 15.58 PLATE-ID=00WQ Comments: position measured from 6717 WF3 image 7760( 9) - 07/29/99 15:16 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 237D TO 257D On Hold Comments: Additional Comments: Visit 1 is an EARLY ACQUISITION for Visit 2. (data from Visit 1 are required to finalise Visit 2). ORIENTations +/- 180 degrees from specified also acceptable. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 A2597-STAR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 1 S ONBOARD ACQ FOR 2-5 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 A2597-NUC STIS/C ACCUM 50CCD MIRROR CR-SPLIT=2 1 100 S CD ------------------------------------------------------------------------------------------------------------------------------------ 3 A2597-NUC STIS/F ACCUM 52X0.5 G140L 1425 1 1800 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 4 A2597-NUC STIS/N ACCUM 52X0.5 G230L 2376 1 1500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 5 A2597-NUC STIS/C ACCUM 52X0.5 G430L 4300 CR-SPLIT=3 1 810 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7760( 9) - 07/29/99 15:16 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 280D TO 310D SCHED 90% On Hold Comments: Additional Comments: Visit 2 requires contiguous orbits, in order to avoid compromising the science objectives. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 A2597-STAR STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 1 S ONBOARD ACQ FOR 2-11 CD P Comments: Orbit 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 A2597-NUC STIS/C ACCUM 50CCD MIRROR CR-SPLIT=2 1 100 S CD Comments: Orbit 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 A2597-LOBE STIS/F TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=120 1 1750 S UV-MAM G A Comments: Orbit 1 ------------------------------------------------------------------------------------------------------------------------------------ 4 A2597-LOBE STIS/F TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=120 1 2550 S UV-MAM G A Comments: Orbit 2 ------------------------------------------------------------------------------------------------------------------------------------ 5 A2597-LOBE STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2 1 720 S POS TARG 0.00, -1.00 CD Comments: Orbit 3 ------------------------------------------------------------------------------------------------------------------------------------ 6 A2597-LOBE STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2 1 720 S POS TARG 0.00, 0.00 CD Comments: Orbit 3 ------------------------------------------------------------------------------------------------------------------------------------ 7 A2597-LOBE STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2 1 720 S POS TARG 0.00, 1.00 CD Comments: Orbit 3 ------------------------------------------------------------------------------------------------------------------------------------ 8 A2597-KNOT STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2 1 800 S POS TARG 0.00, -1.00 CD Comments: Orbit 4 ------------------------------------------------------------------------------------------------------------------------------------ 9 A2597-KNOT STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2 1 800 S POS TARG 0.00, 0.00 CD Comments: Orbit 4 ------------------------------------------------------------------------------------------------------------------------------------ 10 A2597-KNOT STIS/C ACCUM 52X0.2 G430L 4300 CR-SPLIT=2 1 800 S POS TARG 0.00, 1.00 CD Comments: Orbit 4 ------------------------------------------------------------------------------------------------------------------------------------ 7760( 9) - 07/29/99 15:16 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 A2597-KNOT STIS/F TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=120 1 2300 S UV-MAM G A Comments: Orbit 5 ------------------------------------------------------------------------------------------------------------------------------------ 7760( 9) - 07/29/99 15:16 - [ 8] Summary Form for Proposal 7760 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 50CCD 52X0.5 52X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CR-SPLIT=2 CR-SPLIT=3 BUFFER-TIME=120 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO/CAR ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 237D TO 257D ONBOARD ACQ FOR 2-5 ORIENT 280D TO 310D SCHED 90% ONBOARD ACQ FOR 2-11 POS TARG 0.00, -1.00 POS TARG 0.00, 0.00 POS TARG 0.00, 1.00 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140L G230L G430L ------------------------------------------------------------------------------------------------------------------------------------ Target Names A2597-STAR A2597-NUC A2597-LOBE A2597-KNOT ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 2376 4300 ------------------------------------------------------------------------------------------------------------------------------------