Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5416 Report Date: 18-Jul-95:17:20 Version: ********** Check-in Date: ********** 1.Proposal Title: YOUNG GLOBULAR CLUSTERS IN MERGER REMNANTS: CYCLE4 MED ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID GALAXIES & CLUSTERS GO Sub Category STELLAR POPULATIONS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Brad C. Whitmore STSCI USA ------------------------------------------------------------------------------------ 7. Abstract We propose to follow up our cycle 2 HST observations of the merger remnant NGC 7252 with deeper and higher resolution images using the WFPC2, and to extend the project to include one 1-2 Gyr old merger remnant (NGC 3921) and two elliptical galaxies (NGC 1700 and NGC 3610) suspected to be 3-7 Gyr old merger remnants. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 9.82 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5416 PI: Brad C. Whitmore Proposal Title: YOUNG GLOBULAR CLUSTERS IN MERGER REMNANTS: CYCLE4 MED ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Brad C. Whitmore STSCI USA Francois Schweizer DEPARTMENT OF TERRESTRIAL USA MAGNETISM Michael Fall STSCI USA Kirk D. Borne STSCI USA Claus Leitherer STSCI USA X ------------------------------------------------------------------------------------ 3. Description of proposed observations. The Wide Field and Planetary Camera 2 will be used with the filters F555W ("V") and F814W ("I") for all four galaxies. Exposure times will range from 30s (to avoid saturation) to 60 minutes (broken up as needed to fit into orbits of course). The F336W ("U"; 40m) and F439W ("B"; 60m) filters will be used in order to obtain 3 color photometry of NGC 7252. CR-SPLIT will be used for all exposures longer than 10m. The galaxy will always be centered in the PC. Here is a quick summary: F336W F439W F555W F814W NGC 7252 2400 120 60 60 3600 3600 2400 NGC 3921 1200 30 30 2400 1800 NGC 3610 30 30 1200 1000 NGC 1700 60 60 1600 1200 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Briefly, the high-resolution imaging will provide the ability to: 1) determine isophotal diameters of the clusters; 2) distinguish candidate globular clusters (diam < 50 pc) from old OB associations (>200-500 pc); 3) map dust lanes that might interfere with the photometry; and 4) search for double nuclei. One of our key requirements is to determine the luminosity function for the clusters in NGC 7252 to a level which is 3.5 magnitudes fainter than our cycle 2 observations. While the throughput of the WFPC2 is about a factor of 2 worse than the PC for F555W and F785LP, the amount of light within a resolution element of 0.1 arcsec goes up by a factor of 10, due to the improved PSF. This means that the overall gain with WFPC2 will be about a factor of 5, or 1.7 magnitudes. The exposure time for our cycle 2 observations was only 1400 s. Our proposed exposure time for cycle 4 is 7200 s, hence providing another 1.8 magnitude improvement, for a total of 3.5 magnitudes. A detection threshold of V= I= 25 mag, scaled from our cycle 2 observations as described above, was used to determine the exposure times (15 - 40 minutes) for the other galaxies. We note that even with these relatively modest exposure times our detection threshold will be 2 magnitudes fainter than was possible in cycle 2. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. An earlier version of this proposal was awarded supplemental time in cycle 3 (NGC 3610 only). However, it is very unlikely that this will be observed. ------------------------------------------------------------------------------------ 11. Address Information Name: BRAD C. WHITMORE Category: PI Institution: STScI Address: 3700 SAN MARTIN DR. City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 410-338-4743 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5416 [ 3] ------------------------------------------------------------------------------------------------------------------------------------ 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 NGC7252 E, RA = 22H 20M 44.85S +/- 2000 V=4760 1 V=11 303, 320 0.1S, DEC = -24D 40' 42.03" +/- 1" Comments: FLUX IS TOTAL MAGNITUDE OF GALAXY ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC3921 E, RA = 11H 51M 06.93S +/- 2000 V=5975 1 V=14 301, 320 0.1S, DEC = +55D 4' 43" +/- 1", PLATE-ID = 00LK Comments: FLUX IS TOTAL MAGNITUDE OF GALAXY ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC3610 E, RA = 11H 18M 25.2S +/- 0.1S, 2000 V=1765 1 V=13 303, 320 DEC = +58D 47' 10" +/- 1" Comments: FLUX IS TOTAL MAGNITUDE OF GALAXY. NOTE: TARGET IS IN THE CONTINUOUS VIEWING ZONE. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC1700 E, RA = 04H 56M 56.3S +/- 0.1S, 2000 V=3915 1 V=12 303, 320 DEC = -04D 51' 55" +/- 1" Comments: FLUX IS TOTAL MAGNITUDE OF GALAXY ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5416 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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 NGC7252 WFPC2 IMAGE PC1 F336W CR-SPLIT=0.5 1 2400S 1 CYCLE 4 / 1-20 CR- SAME POS FOR 2-7 TOLERANCE=0.1 AS 1 SEQ 1-7 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC7252 WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 1 120S 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC7252 WFPC2 IMAGE PC1 F439W CR-SPLIT=0.5 1 3600S 1 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC7252 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 60S 1 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7252 WFPC2 IMAGE PC1 F555W CR-SPLIT=0.5 1 3600S 1 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC7252 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 60S 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC7252 WFPC2 IMAGE PC1 F814W CR-SPLIT=0.5 1 2400S 1 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC3921 WFPC2 IMAGE PC1 F336W CR-SPLIT=0.5 1 1200S 2 SAME POS FOR 9-12 CR- AS 8 TOLERANCE=0.1 GROUP 8-12 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC3921 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 30S 2 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC3921 WFPC2 IMAGE PC1 F555W CR-SPLIT=0.5 1 2400S 2 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC3921 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 30S 2 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC3921 WFPC2 IMAGE PC1 F814W CR-SPLIT=0.5 1 1800S 2 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC3610 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 30S 3 SAME POS FOR 14-16 AS 13 SEQ 13-16 NO GAP Comments: NOTE: THIS TARGET CAN GO IN THE CVZ. ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC3610 WFPC2 IMAGE PC1 F555W CR-SPLIT=0.5 1 1200S 3 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC3610 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 30S 3 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5416 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC3610 WFPC2 IMAGE PC1 F814W CR-SPLIT=0.5 1 1000S 3 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC1700 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 60S 3 SAME POS FOR 18-20 AS 17 SEQ 17-20 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 18 NGC1700 WFPC2 IMAGE PC1 F555W CR-SPLIT=0.5 1 1600S 3 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ 19 NGC1700 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 60S 3 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC1700 WFPC2 IMAGE PC1 F814W CR-SPLIT=0.5 1 1200S 3 CR- TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5416 [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 CR-TOLERANCE=0.1 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 9.82 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1-20; SAME POS FOR 2-7 AS 1; SEQ 1-7 NO GAP SAME POS FOR 9-12 AS 8; GROUP 8-12 NO GAP SAME POS FOR 14-16 AS 13; SEQ 13-16 NO GAP SAME POS FOR 18-20 AS 17; SEQ 17-20 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F439W F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC7252 NGC3921 NGC3610 NGC1700 ------------------------------------------------------------------------------------------------------------------------------------