8131( 3) - 06/25/99 13:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8131 Version: 3 Check-in Date: 01-Feb-1999 17:26:41 1.Proposal Title: HST Imaging of Moderate Redshift X-ray Emitting Groups of Galaxies ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: John Mulchaey Carnegie Observatories CoI: Dr. Lori Lubin California Institute of Technology N CoI: Dr. Piero Rosati European Southern Observatory N ------------------------------------------------------------------------------------ 5. Abstract Most galaxies in the universe, including our own Milky Way, are members of poor groups of galaxies. Recent optical and X- ray observations of nearby groups have revealed considerable new insight into these important systems. In particular, there are very strong trends between the morphologies of the member galaxies and the global group properties, such as velocity dispersion and the presence of X-ray emitting intragroup gas. To better study evolution in the group environment, we have embarked on a ground-based photometric and spectroscopic survey of a large sample of X-ray selected groups at redshifts of z=0.1-0.5. Our existing ground-based data allow us to determine group membership, derive galaxy colors, and calculate global kinematic properties. However, at these redshifts we lack the ability to quantify galaxy morphology, an essential element in understanding the evolutionary effects occurring in the group environment. Therefore, we propose to obtain WPFC2 images of a subset of our moderate redshift sample. The high angular resolution imagery of HST, combined with our ground-based observations, will allow us to determine the morphological composition of moderate redshift groups, to study how the galaxy population of groups has evolved in time, to examine the Butcher-Oemler effect in the group environment, and to search for direct evidence of mergers and/or galaxy- galaxy encounters in these systems. ------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 2] Observations Description ------------------------ In order to study a statistical sample of groups as well as to request a reasonable amount of observing time, we have chosen to observe only a subset of our intermediate redshift, X-ray selected group sample. The HST sample contains 9 groups of galaxies. Most of the HST observations of moderate redshift clusters have been made in the F702W filter. Since we are interesting in comparing the evolution of galaxies in groups to those in clusters, we have chosen to image our sample with the F702W filter. This filter is the most efficient choice for imaging groups of galaxies at z = 0.2 - 0.5, given the typical spectral energy distribution of the group galaxies combined with the relatively high QE and broad bandpass of this filter. This band also corresponds to the well-studied B and V bands over our observed range in redshift. For each of these bands, we have existing data on nearby X-ray detected groups (Zabludoff & Mulchaey 1998). In order to estimate our observing times, we have examined previous HST data from observations of moderate redshift clusters (e.g.\ Smail et al.\ 1997). We are interested in obtaining morphologies for all galaxies in our groups more luminous than M_* + 3, the limit of our ground- based photometric data. Smail et al.\ (1997) determined that for their z ~ 0.4-0.5 sample, they could visually classify objects with a total magnitude of R_ 702 < 23.5. This magnitude corresponds to slightly fainter than M_* + 3 for our most distant (i.e. z ~ 0.45) groups. Smail et al.\ (1997) reached this level with the WFC chips in exposure times of ~ 10 ksec. Including overhead for read-out and guide star acquisition, exposures of this length require ~ 4 orbits. Thus, we request four orbits for each of our groups in the z = 0.4-0.5 range. The exposure times required to achieve our target of M_* + 3 is progressively less for our lower redshift groups. Real Time Justification ----------------------- None. There are no supporting observations which affect the scheduling of this HST proposal. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS- CLUSTER OF GALAXIES, RA=02H 10M 26.49S +/- 0.1S, J2000 Z=0.305 SURF(V) = 24.5+/-1.0 021026- Group, Poor Cluster DEC=-39D 29' 31.7" +/- 0.2", 392932 PLATE-ID=00AL 2 GAL-CLUS- CLUSTER OF GALAXIES, RA=03H 29M 3.7S +/- 0.1S, J2000 Z=0.45 SURF(V) = 25.0+/-1.0 032904+02561 Group, Poor Cluster DEC=+02D 56' 12.7" +/- 0.2", 3 PLATE-ID=04YK 3 GAL-CLUS- CLUSTER OF GALAXIES, RA=03H 41M 57.9S +/- 0.1S, DEC= J2000 Z=0.41 SURF(V) = 24.8+/-1.0 034158- Group, Poor Cluster -44D 59' 52.0" +/- 0.2", PLATE- 445952 ID=04FM 4 GAL-CLUS- CLUSTER OF GALAXIES, RA=07H 20M 56.0S +/- 0.1S, J2000 Z=0.228 SURF(V) = 24.0+/-1.0 072056+71084 Group, Poor Cluster DEC=+71D 08' 43.4" +/- 0.2", 3 PLATE-ID=01KS 5 GAL-CLUS- CLUSTER OF GALAXIES, RA=12H 05M 55.4S +/- 0.1S, J2000 Z=0.35 SURF(V) = 24.4+/-1.0 120555+44293 Group, Poor Cluster DEC=+44D 29' 35.0" +/- 0.2", 5 PLATE-ID=024C 6 GAL-CLUS- CLUSTER OF GALAXIES, RA=12H 56M 2.68S +/- 0.1S, J2000 Z=0.232 SURF(V) = 24.0+/-1.0 125603+25564 Group, Poor Cluster DEC=+25D 56' 42.2" +/- 0.2", 2 PLATE-ID=01PN 7 GAL-CLUS- CLUSTER OF GALAXIES, RA=13H 35M 2.54S +/- 0.1S, J2000 Z=0.384 SURF(V) = 24.6+/-1.0 133503+37500 Group, Poor Cluster DEC=+37D 50' 07.85" +/- 0.2", 8 PLATE-ID=01QW 8 GAL-CLUS- CLUSTER OF GALAXIES, RA=13H 47M 57.7S +/- 0.1S, J2000 Z=0.470 SURF(V) = 25.2+/-1.0 134758+07522 Group, Poor Cluster DEC=+07D 52' 23.6" +/- 0.2", 4 PLATE-ID=019P 9 GAL-CLUS- CLUSTER OF GALAXIES, RA=16H 48M 42.0S +/- 0.1S, J2000 Z=0.377 SURF(V) = 24.7+/-1.0 164842+60191 Group, Poor Cluster DEC=+60D 19' 10.0" +/- 0.2", 0 PLATE-ID=00T2 8131( 3) - 06/25/99 13:58 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 90D to 180D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-02 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=LINE, 1 2700.00 1026-392932 DITHER-LINE-STEPS=3 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 285D to 345D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-03 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=BOX,CR-SPLIT=NO 1 2600.00 2904+025613 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ORIENT 280D to 350D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-03 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=BOX,CR-SPLIT=NO 1 2800.00 4158-445952 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 7] Visit: 04 Visit Priority: Visit Requirements: ORIENT 280D to 350D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-07 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=LINE 1 2700.00 2056+710843 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 8] Visit: 05 Visit Priority: Visit Requirements: ORIENT 250D to 290D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-12 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=LINE, 1 2700.00 0555+442935 DITHER-LINE-STEPS=3 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 9] Visit: 06 Visit Priority: Visit Requirements: ORIENT 305D to 325D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-12 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=LINE 1 2300.00 5603+255642 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 10] Visit: 07 Visit Priority: Visit Requirements: ORIENT 295D to 335D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-13 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=LINE, 1 2700.00 3503+375008 DITHER-LINE-STEPS=3 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 11] Visit: 08 Visit Priority: Visit Requirements: ORIENT 150D to 210D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-13 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=BOX,CR-SPLIT=NO 1 2600.00 4758+075224 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 12] Visit: 09 Visit Priority: Visit Requirements: ORIENT 80D to 120D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS-16 WFPC2 IMAGE WF3-FIX F702W 6868 DITHER-TYPE=LINE, 1 2700.00 4842+601910 DITHER-LINE-STEPS=3 ------------------------------------------------------------------------------------------------------------------------------------ 8131( 3) - 06/25/99 13:58 - [ 13] Summary Form for Proposal 8131 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WF3-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DITHER-TYPE=LINE DITHER-LINE-STEPS=3 CR-SPLIT=NO DITHER-TYPE=BOX ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 90D to 180D ORIENT 285D to 345D ORIENT 280D to 350D ORIENT 250D to 290D ORIENT 305D to 325D ORIENT 295D to 335D ORIENT 150D to 210D ORIENT 80D to 120D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F702W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GAL-CLUS-021026-392932 GAL-CLUS-032904+025613 GAL-CLUS-034158-445952 GAL-CLUS-072056+710843 GAL-CLUS-120555+442935 GAL-CLUS-125603+255642 GAL-CLUS-133503+375008 GAL-CLUS-134758+075224 GAL-CLUS-164842+601910 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 6868 ------------------------------------------------------------------------------------------------------------------------------------