6675( 5) - 05/21/97 12:21 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6675 Version: 5 Check-in Date: 21-May-1997 12:20:32 1.Proposal Title: The Evolution of Galaxies in Groups ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle COSMOLOGY GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: ESTHER ZIRBEL HAVERFORD COLLEGE CoI: Augustus Oemler Yale University N CoI: Jeremy Allington-Smith Durham University N CoI: Richard Ellis Cambridge University N CoI: Mark Dickinson Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract There is now convincing evidence that galaxy evolution has progressed as a strong function of the environment. The strongest evolution is seen in the cores of rich clusters, which, at the present epoch, are dominated by red, early type galaxies, whereas comparable clusters at z ~ 0.4 have blue star-forming spiral galaxies in addition to galaxies with disturbed morphologies. The evolution of galaxies in the field is milder and observed mostly among low luminosity irregular galaxies. The marked contrast between the rich cluster and field results makes it difficult to construct a convincing unified picture of what environmental processes are driving galaxy evolution. Here we propose to observe galaxies in small groups at z ~ 0.4, that ``bridge'' the 10^4 density gap between the two environmental extremes. We will determine the morphological mix of galaxies in groups to examine how this depends on group richness. Furthermore, we will compare the frequency and severity of the morphological disturbances of galaxies in groups to those of galaxies in the field and in rich clusters. This analysis will help confine those environmental mechanisms that transform galaxies. We propose to obtain HST images with the F702W filter of 10 groups, which have already been extensively studied photometrically and spectroscopically. With 10 4-orbit observations we will get a large enough and deep enough sample to study galaxy evolution over a range of environments. ------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 2] Observations Description ------------------------ We will employ the F702W filter for maximum throughput, and to simplify direct comparison with the Dressler Etal and Oemler Etal cluster data which is obtained with the same bandpass. The Medium Deep Survey, which provides comparable data on field galaxies, uses the F814W filter. For our purpose this wavelength difference is insignificant. At the median redshift of our sample, F702W corresponds to roughtly the rest frame V-band. Our aim is to determine the morphological mix of galaxies as a function of environment and to compare that to cluster and Medium Deep Survey results. HST Cycle 4 and 5 observations of z ~ 0.4 clusters have demonstrated that after 10 orbits integration morphologies can be determined down to r ~ 23 while subtler morphological features like tails, bridges can be seen one magnitude brighter than that limit. Although it would be desirable to go as deep on individual systems as in cluster observations, it is preferable to obtain adequate exposures on a large sample. With 4 orbits per field, this means that galaxy morphologies can be determined down to r ~ 22.5 (this was calculated by degrading the 10 orbit F720W WFPC-2 observation of CL 0939+47, a z = 0.41 cluster, by adding poisson noise and including the additional readout noise generated by the use of a CR- SPLIT in the observing sequence). Altogether we plan to observe 10 groups spanning a range of richnesses and thus bridgeing the gap between HST morphological studies of rich clusters and the field. Real Time Justification ----------------------- None. Our ground based imaging data (published by Allington-Smith Etal) on the radio-selected groups provides rest-frame B-V photometry, group richness, and blue fractions of all fields. Altogether we possess photometry on 74 z ~ 0.4 and LDSS-2 multislit spectra of galaxies in 3 groups. In addition we have been allocated 5 nights on the 4m telescope time in October at Kitt Peak (using CryoCam) to obtain additional spectra of galaxies in 8 more groups. The aim is to confirm galaxy-by-galaxy group membership, quantify spectral properties to determine the stellar populations of those galaxies, and to obtain velocity dispersions to analyze the dynamics of those groups. In addition, for 3 of the 10 groups of our HST sample, Dickinson (1994) has observations in 6 filters and multislit spectroscopy from the Paloma 5m telescope. Presently we are continuing the extensive spectroscopic followup program using LDSS-2 on WHT, CryoCam at KPNO and Hydra on WIYN. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3C16 GALAXY,RADIO RA=00H 35M 09.16S +/- B1950.0 Z = V = 21.1+/-0.5 GALAXY,BRIGHTEST GROUP 1.0",DEC=13D 03' 39.6" +/- 1.0" 0.405 MEMBER,CLUSTER OF GALAXIES,GROUP,POOR Comments: radio-selected group of galaxies Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B1950.0 0.0 0.0 0.0 2 5C6.124 GALAXY,RADIO RA=02H 13M 43.2S +/- B1950. Z = V = 21.0+/-0.5 GALAXY,BRIGHTEST GROUP 1.0",DEC=32D 36' 54" +/- 1.0" 0.448 MEMBER,CLUSTER OF GALAXIES,GROUP,POOR Comments: radio-selected group of galaxies Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B1950.0 0.0 0.0 0.0 3 5C12.251 GALAXY,BRIGHTEST GROUP RA=10H 03M 31.9S +/- B1950.0 Z = V = 20.1+/-0.5 MEMBER,RADIO 1.0",DEC=36D 55' 29.7" +/- 1.0" 0.312 GALAXY,CLUSTER OF GALAXIES,GROUP,POOR Comments: radio-selected group of galaxies Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950.0 0.0 0.0 0.0 4 3C435A GALAXY,RADIO RA=21H 26M 37.35S +/- B1950.0 Z = V = 21.0+/-0.5 GALAXY,BRIGHTEST GROUP 1.0",DEC=07D 19' 49.4" +/- 1.0" 0.471 MEMBER,CLUSTER OF GALAXIES,GROUP,POOR Comments: radio-selected group of galaxies; 3C435B (z=0.865) also in field; coordinates are for modpoint position between 3C435A & B. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B1950.0 0.0 0.0 0.0 5 PKS0101+023 GALAXY,RADIO RA=01H 01M 49.4S +/- B1950.0 Z = V = 19.5+/-0.5 GALAXY,BRIGHTEST GROUP 1.0",DEC=02D 23' 38" +/- 1.0" 0.390 MEMBER,CLUSTER OF GALAXIES,GROUP,POOR Comments: radio-selected group of galaxies Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950.0 0.0 0.0 0.0 6 4C27.51 GALAXY,RADIO RA=23H 22M 30.4S +/- B1950.0 Z = V = 18.5+/-0.5 GALAXY,BRIGHTEST GROUP 1.0",DEC=27D 46' 55" +/- 1.0" 0.319 MEMBER,CLUSTER OF GALAXIES,GROUP,POOR Comments: radio-selected goup of galaxies Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B1950.0 0.0 0.0 0.0 6675( 5) - 05/21/97 12:21 - [ 5] Visit: 01 Visit Requirements: ORIENT 0D TO 90D 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 3C16 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 3C16 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 3C16 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 3C16 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1000 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 5 3C16 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 6 3C16 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S POS TARG -10.046,-10.046 ------------------------------------------------------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 7 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 8 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 9 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 10 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 11 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 12 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 13 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 14 5C6.124 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 7] Visit: 03 Visit Requirements: ORIENT 20D TO 100D 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 ------------------------------------------------------------------------------------------------------------------------------------ 15 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG 0.0,0.0 ------------------------------------------------------------------------------------------------------------------------------------ 16 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG 0.0,0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG 0.0,0.0 ------------------------------------------------------------------------------------------------------------------------------------ 18 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG 0.0,0.0 ------------------------------------------------------------------------------------------------------------------------------------ 19 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S POS TARG 0.0,0.0 ------------------------------------------------------------------------------------------------------------------------------------ 20 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1000 S EXPAND POS TARG -1.046, -1.046 ------------------------------------------------------------------------------------------------------------------------------------ 21 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -1.046, -1.046 ------------------------------------------------------------------------------------------------------------------------------------ 22 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -1.046, -1.046 ------------------------------------------------------------------------------------------------------------------------------------ 23 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -1.046, -1.046 ------------------------------------------------------------------------------------------------------------------------------------ 24 3C435A WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -1.046, -1.046 ------------------------------------------------------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 8] Visit: 04 Visit Requirements: ORIENT 270D TO 130D 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 ------------------------------------------------------------------------------------------------------------------------------------ 25 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 26 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 27 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 28 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 29 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 30 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 31 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 32 PKS0101+023 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 9] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: PREFERRED ORIENT IS ACTUALLY 30D AND PREFERRED RANGE WAS ORIENT 0D TO 60D, BUT THAT RESULTED IN NO SCHEDULABILITY IN RPS2. NEXT PREFERENCE IN ORIENT RANGE WAS ORIENT 340D TO 80D BUT THAT ALSO DID NOT PRODUCE ANY SCHEDULABILITY, THEREFORE THE ORIENT WAS REMOVED ALTOGETHER. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 33 5C12.251 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 34 5C12.251 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 35 5C12.251 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 36 5C12.251 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1300 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 10] Visit: 06 Visit Requirements: ORIENT 220D TO 45D On Hold Comments: Additional Comments: First preference on ORIENT was for range of ORIENT 220D TO 320D, but since it was found unschedulable by Spike, it was relaxed to ORIENT 220D TO 45D by the PI. If possible, however, STScI should try to keep as near as possible to original preference provided that sky background scattered light is not too bad at the ultimate chosen ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 37 4C27.51 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 38 4C27.51 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -9.0,-9.0 ------------------------------------------------------------------------------------------------------------------------------------ 39 4C27.51 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 40 4C27.51 WFPC2 IMAGE PC1 F702W CR-SPLIT=no 1 1200 S EXPAND POS TARG -10.046, -10.046 ------------------------------------------------------------------------------------------------------------------------------------ 6675( 5) - 05/21/97 12:21 - [ 11] Summary Form for Proposal 6675 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=no ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category COSMOLOGY ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 0D TO 90D EXPAND POS TARG -9.0,-9.0 EXPAND POS TARG -10.046,-10.046 ORIENT 20D TO 100D EXPAND POS TARG 0.0,0.0 EXPAND POS TARG -1.046,-1.046 ORIENT 270D TO 130D ORIENT 220D TO 45D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F702W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3C16 5C6.124 3C435A PKS0101+023 5C12.251 4C27.51 ------------------------------------------------------------------------------------------------------------------------------------