Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5709 Report Date: 18-Jul-95:17:53 Version: ********** Check-in Date: ********** 1.Proposal Title: STAR FORMATION RATES IN DISTANT CLUSTER GALAXIES: CYCLE 4 CARRY-OVER ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID GALAXIES & CLUSTERS AUG/FOC 4072 Sub Category EVOLUTION/COSMOLOGY ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Jean-michel Deharveng LABORATOIRE ASTRONOMIE SPATI FRANCE (33) 91055917 ------------------------------------------------------------------------------------ 7. Abstract Multicolor photometry and spectroscopic redshifts are available for a complete sample of faint galaxies in the southern cluster Abell 370 at a redshift of z=0.37. Strong evidence has been found for residual star formation in the red cluster galaxies. This may reflect general evolution in the cluster ellipticals, or it could represent the final transition from infalling gas-rich systems to present-day lenticular galaxies. WFPC2 will be used to extend the spectral energy distributions for cluster members into the UV providing direct measures of the proportions of young and evolved stars in a carefully selected sample of red members complete to K=17.0. ------------------------------------------------------------------------------------ 8. Scientific Key Words: EARLY-TYPE GALAXY, EVOLUTION GALAXY CLUSTER ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 10.11 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5709 PI: Dr. Jean-michel Deharveng Proposal Title: STAR FORMATION RATES IN DISTANT CLUSTER GALAXIES: CYCLE 4 CARRY-OVER ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Richard Ellis PHYSICS DEPARTMENT, UNIVERSITY UK X OF DURHAM Craig Mackay INSTITUTE OF ASTRONOMY, UK X CAMBRIDGE Page 3 ------------------------------------------------------------------------------------ 3. Description of proposed observations. We aim to obtain exposures of each of selected early-type cluster members through the filters F255W and F336W. Our implementation preferences are as follows: First preference: Our first preference is that all exposures in this program be taken together NO GAP, using the same guide stars, and maintaining the SAME ORIENT. Doing the observations NO GAP and using the same guide stars will allow us to ensure the accuracy of the small POS TARG offsets we are doing, and will also help in maintaining the SAME ORIENT. If we are photon-starved, we could thus very reliably register and co-add all the frames in all the filters together if need be. Second preference: Our second preference is that Exposure Log lines 1-5 and 6-12 each be done NO GAP and still using the SAME ORIENT and same guide stars for ALL exposures, 1-12. The two groups of exposures should be done within a week's period so that the requirements of using the same guide stars and keeping the SAME ORIENT are more readily preserved, and the calibration should be very similar, minimizing any temporal variations as much as possible. The "WITHIN 7 DAYS" requirement may be relaxed if necessary for scheduling, but we prefer it to remain so that all the exposures are done within the amount of time necessary to maintain the SAME ORIENT and the use of the same guide stars. Again, if we are photon-starved, we can at least preserve the registration of pointing and offsets for all exposures. We can co-add the frames in the two filters at least, and may still be able to co-add all of the exposures ( 1-12 ) very well if the same guide stars and SAME ORIENT are still used for 1-12. Breaking the exposures into two separate sub-groups ( 1-5 and 6-12 ) allows a break for SAA passages, etc. if needed. Absolute ORIENT angle preferences: The absolute ORIENT=255D +/- 30D may be changed if needed for scheduling, but we request that we be consulted on any change so that we can help pick the next best alternate ORIENT angles to maximize the number of cluster galaxies in the WFPC2 field of view. POS TARG offsets, hot pixels, and cosmic rays: For all our sets of exposures per filter, the small POS TARG offsets are being done to overcome hot pixels, etc. Also, the dithering using the POS TARG offsets has been done taking into account the SUM 2x2, so that the dithering is done by an integral multiple of 2 pixels rather than one. We have used POS TARG values of 0.4 here based upon advice from John Biretta, WFPC2 Instrument Scientist. Exposure times and cosmic rays: After initial tests with STScI's implementation software, which gave us a better idea of actual exposure times available, we have instead specified individual exposures, all with CR-SPLIT=NO, simply shortening the first of the longest exposures in both F255W and F336W in order to allow time for the initial full guide star acquisition during the first orbit. This exposure time cut for the first exposure should not have a dramatic impact on our S/N. We will shift and register the frames in order to remove cosmic rays when doing the data reduction and analysis. We will be able to use the multiple exposures in F255W and F336W to remove cosmic rays in those exposures. Hot pixels can be dealt with in all filters due to the shifts. Summary: As we mentioned earlier, in case we are photon-starved, we may be able to co-add exposures in different filters if the NO GAP/SAME ORIENT/same guide stars requirements are maintained to tie together all the exposures in this program. As mentioned before, if it is necessary to break this requirement, the minimum requirement is that all exposures in each filter be done NO GAP, at the SAME ORIENT, and using the same guide stars. We also wish all exposures to be done within the period of time in which the ORIENT window is available rather than having to wait another year to complete all exposures. If necessary for scheduling, the absolute ORIENT angle may be dropped or at least changed, but we request that you contact us and discuss this option with us if it becomes necessary. Implementation Notes: After initial runs of TRANS better illustrated what should work and what would not, we decided to use individually-specified exposures with CR-SPLIT=NO and exposure times adjusted to fit as needed. The "second preference" option above has been chosen also since the 1-12 NO GAP option ran into trouble with the SAA and needed to be broken. Effectively, this means that 1-5 and 6-12 should still each be done NO GAP, and all exposures ( 1-12 ) should still be done within 7 days. Likewise, all of them ( 1-12 ) should still use the same guide stars, and be done at the SAME ORIENT angle. Page 4 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. UV astronomy cannot be performed from ground-based observatories. no UV facilities other than HST are adequate for faint galaxies. ------------------------------------------------------------------------------------ 9. Description of previous HST work. GTO program 1246 ------------------------------------------------------------------------------------ 11. Address Information Name: Jean-Michel Deharveng Category: PI Institution: Laboratoire Astronomie Spatiale Address: Traverse du Siphon, Les Trois Lucs BP8-13376 MARSEILLE Cedex 12 City: Marseille State: Zip Code: Country: France Telephone: (33)91055917 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5709 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 ABELL370 F,404,E,303 RA = 2H 37M 20.8S +/- 0.2S, 1950 Z = 0.37 1 R = 18.47 DEC = -1D 47' 32.3" +/- 3" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5709 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 ABELL370 WFPC2 IMAGE WFALL- F255W SUM=2x2 1 2000S 5 1 1 CYCLE 4 / 1-12 FIX CR-SPLIT=NO SEQ 1-5 NO GAP ORIENT 255D +/- 30D SAME ORIENT FOR 2- 12 AS 1 Comments: DO ALL EXPOSURES IN THIS GROUP 1-5, 6-12 PROGRAM WITHIN 7 DAYS. PLEASE WITHIN 7D USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 2 ABELL370 WFPC2 IMAGE WFALL- F255W SUM=2x2 1 2400S 5 1 1 SAME POS FOR 2-3 FIX CR-SPLIT=NO AS 1 Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 3 ABELL370 WFPC2 IMAGE WFALL- F255W SUM=2X2 1 2400S 5 1 1 FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 4 ABELL370 WFPC2 IMAGE WFALL- F255W SUM=2x2 1 2400S 5 1 1 POS TARG +0.4,+0.4 FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5709 [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 ABELL370 WFPC2 IMAGE WFALL- F255W SUM=2x2 1 2400S 5 1 1 POS TARG +0.4,+0.4 FIX CR-SPLIT=NO SAME POS FOR 5 AS 4 Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 6 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2000S 5 1 1 SEQ 6-12 NO GAP FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 7 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2400S 5 1 1 SAME POS FOR 7-9 FIX CR-SPLIT=NO AS 6 Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 8 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2400S 5 1 1 FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 9 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2400S 5 1 1 FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5709 [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2400S 5 1 1 POS TARG +0.4,+0.4 FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 11 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2400S 5 1 1 SAME POS FOR 11-12 FIX CR-SPLIT=NO AS 10 POS TARG +0.4,+0.4 Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ 12 ABELL370 WFPC2 IMAGE WFALL- F336W SUM=2x2 1 2400S 5 1 1 POS TARG +0.4,+0.4 FIX CR-SPLIT=NO Comments: DO ALL EXPOSURES IN THIS PROGRAM WITHIN 7 DAYS. PLEASE USE SAME GUIDE STARS FOR ALL EXPOSURES. SMALL POS TARG OFFSETS ARE USED TO HELP WITH HOT PIXELS, ETC. CALL PI IF ORIENT IS A PROBLEM. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5709 [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SUM CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for AUG/FOC ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 10.11 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category EVOLUTION/COSMOLOGY ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1-12; SEQ 1-5 NO GAP; ORIENT 255D +/- 30D; SAME ORIENT FOR 2-12 AS 1; GROUP 1-5, 6-12 WITHIN 7D; SAME POS FOR 2-3 AS 1; POS TARG +0.4,+0.4; SAME POS FOR 5 AS 4; SEQ 6-12 NO GAP; SAME POS FOR 7-9 AS 6; SAME POS FOR 11-12 AS 10; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F255W F336W ------------------------------------------------------------------------------------------------------------------------------------ Target Names ABELL370 ------------------------------------------------------------------------------------------------------------------------------------