5917( 4) - 11/20/95 14:05 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5917 Version: 4 Check-in Date: ********** 1.Proposal Title: The Globular Clusters in the Fornax Dwarf Galaxy-Physical Parameters and Chronology ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Stellar Populations GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Robert Zinn Yale University CoI: Flavio Fusi Pecci Osservatorio Astronomico di Bologna N CoI: Carla Cacciari Osservatorio Astronomico di Bologna N CoI: Roberto Buonanno Rome Observatory N CoI: Eduardo Hardy Laval University N CoI: Nicholas Suntzeff Cerro Tololo Observatory N ------------------------------------------------------------------------------------ 6. Abstract From photometry of the four most metal-poor globular clusters in the Fornax Dwarf Spheroidal Galaxy with the WFPC2, we will: (1) measure their ages, (2) study their populations of blue stragglers, (3) measure their horizontal branch (HB) morphologies, (4) measure their He and metal abundances Fe/H, and (5) their radial density profiles. The HST is required because only it has the resolution and faint limiting magnitude necessary to reach the main- sequence turnoffs in the central regions of the clusters, where cluster stars greatly out number field stars. Our results for (1) will indicate the duration of metal-poor cluster formation in this very low-mass galaxy and test the relationship between cluster age and HB morphology. (4) will provide the first estimate of He abundance in this galaxy. (2, 3, 4, 5) will reveal how the Fornax globulars compare with ones in the Milky Way in terms of their stellar populations and structures. A comparison of the apparent magnitudes of their HB's will test predictions of the HB luminosity-Fe/H relationship. Our results will provide valuable information on the evolution of globular clusters and low-mass galaxies. This proposal is a updated version of one which recieved time in Cycle 1 (had to be deferred) and supplemental time in Cycle 4. ------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 2] Observations Description ------------------------ The PC will be used to photometer the high density central regions of the 4 clusters, while the WF chips will record the outer regions of the clusters and the star fields surrounding the clusters. Since the PC data are the critical ones for this project, the exposure times are based on its characteristics. Multiple long exposures (5x1500s in F814W and 5x1000s in F555W), with shifts in position in between the pairs of exposures, will produce S/N = 10 at V=26, which is 1.2 mag. fainter than the expected location of the main-sequence turnoffs in the clusters. These observations will reveal the blue straggler populations of the clusters and will provide the means to measure their ages. The horizontal branch stars are not saturated on these frames; hence they will be used to measure the horizontal branch morphologies of the clusters. The giant branches of the clusters will be measured from multiple short exposures (6x120s in F814W and 5x160s in F555W). The brightest red giants will not saturate on these individual exposures, while together they will provide good S/N at the region of overlap with the long exposures (S/N=50 at V=20.0). Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 FORNAX- EXT-CLUSTER,GLOBULAR RA = 02H 37M 1.97S +/- 2.0", DEC 2000 V=26.0+/-0.1 023702- CLUSTER = -34D 11' 2.8" +/- 2.0", PLATE- B-V=0.60+/-0.05 341103 ID=047Z E(B-V)=0.03+/-0.03 Comments: Flux at 1.2 mag. below m-s turnoff 2 FORNAX- EXT-CLUSTER,GLOBULAR RA = 02H 38M 44.25S +/- 2.0", 2000 V = +52 V=26.0+/-0.1 023844- CLUSTER DEC = -34D 48' 32.9" +/- 2.0", B-V=0.60+/-0.05 344833 PLATE-ID=02IV E(B-V)=0.03+/-0.03 Comments: Flux at 1.2 mag. below m-s turnoff 3 NGC1049 EXT-CLUSTER,GLOBULAR RA = 02H 39M 48.14S +/- 2.0", 2000 V = +59 V=26.0+/-0.1 CLUSTER DEC = -34D 15' 31.7" +/- 2.0", B-V=0.60+/-0.05 PLATE-ID=02IV E(B-V)=0.03+/-0.03 Comments: Flux at 1.2 mag. below m-s turnoff 4 FORNAX- EXT-CLUSTER,GLOBULAR RA = 02H 42M 21.17S +/- 2.0", 2000 V = +62 V=26.0+/-0.1 024221- CLUSTER DEC = -34D 06' 8.3" +/- 2.0", B-V=0.60+/-0.05 340608 PLATE-ID=02IV E(B-V)=0.03+/-0.03 Comments: Flux at 1.2 mag. below m-s turnoff 5917( 4) - 11/20/95 14:05 - [ 4] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15,CR- 4 160S 023702- SPLIT=NO 341103 ------------------------------------------------------------------------------------------------------------------------------------ 2 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15,CR- 6 120S SAME POS AS 1 023702- SPLIT=NO 341103 ------------------------------------------------------------------------------------------------------------------------------------ 3 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 4 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 3 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 5 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG +0.501,-0.501 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 6 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 5 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 7 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG -0.501,+0.501 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 8 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 7 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 9 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG -0.501,-0.501 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 10 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 9 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 11 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG +0.501,+0.501 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 11 023702- 341103 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15,CR- 4 160S 023844- SPLIT=NO 344833 ------------------------------------------------------------------------------------------------------------------------------------ 2 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15,CR- 6 120S SAME POS AS 1 023844- SPLIT=NO 344833 ------------------------------------------------------------------------------------------------------------------------------------ 3 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 4 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 3 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 5 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG +0.501,-0.501 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 6 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 5 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 7 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG -0.501,+0.501 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 8 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 7 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 9 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG -0.501,-0.501 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 10 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 9 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 11 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG +0.501,+0.501 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 11 023844- 344833 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 8] Visit: 03 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC1049 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15,CR- 4 160S SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC1049 WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15,CR- 6 120S SAME POS AS 1 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC1049 WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC1049 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 3 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC1049 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG +0.501,-0.501 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC1049 WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 5 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC1049 WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG -0.501,+0.501 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC1049 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 7 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC1049 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG -0.501,-0.501 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC1049 WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 9 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC1049 WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG +0.501,+0.501 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC1049 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 11 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 9] Visit: 04 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15,CR- 4 160S 024221- SPLIT=NO 340608 ------------------------------------------------------------------------------------------------------------------------------------ 2 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15,CR- 6 120S SAME POS AS 1 024221- SPLIT=NO 340608 ------------------------------------------------------------------------------------------------------------------------------------ 3 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 4 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 3 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 5 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG +0.501,-0.501 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 6 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 5 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 7 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG -0.501,+0.501 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 8 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 7 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 9 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S POS TARG -0.501,-0.501 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 10 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S SAME POS AS 9 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 11 FORNAX- WFPC2 IMAGE PC1-FIX F814W ATD-GAIN=15 1 1400S POS TARG +0.501,+0.501 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 10] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 FORNAX- WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=15 1 1000S SAME POS AS 11 024221- 340608 ------------------------------------------------------------------------------------------------------------------------------------ 5917( 4) - 11/20/95 14:05 - [ 11] Summary Form for Proposal 5917 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=15 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Stellar Populations ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SAME POS AS 1 SAME POS AS 3 POS TARG +0.501,-0.501 SAME POS AS 5 POS TARG -0.501,+0.501 SAME POS AS 7 POS TARG -0.501,-0.501 SAME POS AS 9 POS TARG +0.501,+0.501 SAME POS AS 11 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names FORNAX-023702-341103 FORNAX-023844-344833 NGC1049 FORNAX-024221-340608 ------------------------------------------------------------------------------------------------------------------------------------