Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3227c Report Date: 09-May-96:18:12 Version: ********** Check-in Date: ********** 1.Proposal Title: THE STELLAR DENSITY DISTRIBUTIONS IN THE CENTERS OF GALACTIC GLOBULAR CLUSTERS: CYCLE 1 OBSERVATIONS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR POPULATIONS GTO/OS 1019 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. John N. Bahcall INSTITUTE FOR ADVANCED STUDY USA (609) 734-8054 DR. JOHN N. BAHCALL ------------------------------------------------------------------------------------ 7. Abstract Short exposures will be made of all galactic globular clusters with distance moduli less than 15.5 mag and galactic latitude above or below 15 degrees. A search will be made for cusps in the stellar density distributions and the colors will be measured for the brightest stars in the cores of the clusters. ST observations are required in order to reach the innermost regions of the clusters with sufficient resolution to separate individual stars. ------------------------------------------------------------------------------------ 8. Scientific Key Words: GLOBULAR CLUSTER, POPULATION II, BLACK HOLE ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0.25 par: 0 10. Num targs pri: 20 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3227c PI: Dr. John N. Bahcall Proposal Title: THE STELLAR DENSITY DISTRIBUTIONS IN THE CENTERS OF GALACTIC GLOBULAR CLUSTERS: CYCLE 1 OBSERVATIONS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ John N. Bahcall INSTITUTE FOR ADVANCED STUDY USA Neta A. Bahcall SPACE TELESCOPE SCIENCE USA INSTITUTE ------------------------------------------------------------------------------------ 3. Description of proposed observations. Two exposures will be taken for each object. They need not be consecutive, but the telescope roll angle should be the same for both exposures. This series of exposures will give both colors (V and I) and number densities for the brightest stars in the central regions of the globular clusters. Cycle 1 (SV: 1-6 months) plus Cycle 2 (7-18 months) = Exposures 1-40. The target position should be placed at the center of one CCD, immaterial which one. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. ST observations are required in order to resolve individual stars in the cores of the globular clusters in sufficient numbers to permit a determination of the stellar density law. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The telescope roll angle should be the same for both exposures on a given cluster, although the two exposures on a cluster need not be consecutive. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data reduction and analysis will be performed at both the Institute for Advanced Study and at STScI. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. The target position should be placed at the center of one CCD, immaterial which one. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Computing support and research associates will be available at both IAS and STScI as required by the science. ------------------------------------------------------------------------------------ 13. Short exposures will be made of all galactic globular clusters with distance moduli less than 15.5 mag and galactic latitude above 15 degrees. A search will be made for cusps in the stellar density distributions and the colors will be measured for the brightest stars in the cores of the clusters. Short exposures will be made of all galactic globular clusters with distance moduli less than 15.5 mag, estimated core radii less than 1 arc minute, and galactic latitude above 15 degrees. We will search for a cusp in the stellar density distribution. ------------------------------------------------------------------------------------ 11. Address Information Page 3 Name: JOHN N. BAHCALL Category: PI Institution: INSTITUTE FOR ADVANCED STUDY Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3227c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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 NGC362 GALACTIC GLOBULAR RA = 01H 01M 32.87S +/- 1950 1 SURF(V) = 15.0 +/- 0.2 CLUSTER 0.1S, DEC = -71D 06' 58.4" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4590 M68 ^ RA = 12H 36M 48.71S +/- 1950 1 SURF(V) = 17.92 +/- 0.2 0.1S, DEC = -26D 28' 06.4" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5904 M5 ^ RA = 15H 16M 01.90S +/- 1950 1 SURF(V) = 16.10 +/- 0.2 0.1S, DEC = +02D 15' 50.9" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6218 M12 ^ RA = 16H 44M 38.63S +/- 1950 1 SURF(V) = 18.23 +/- 0.2 0.1S, DEC = -01D 51' 33.9" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC6362 ^ RA = 17H 26M 44.83S +/- 1950 1 SURF(V) = 19.15 +/- 0.2 0.1S, DEC = -67D 00' 38.5" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC7099 M30 GALACTIC GLOBULAR RA = 21H 37M 31.64S +/- 1950 1 SURF(V) = 15.12 +/- 0.2 CLUSTER 0.1S, DEC = -23D 24' 23.1" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3227c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC362 PC IMAGE P6 F785LP PRE-FLASH=YES 1 100S 1 2 GUIDE TOL 0.019" / 1-12 CYCLE 1 / 1-12 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4590 PC IMAGE P6 F785LP PRE-FLASH=YES 1 100S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5904 PC IMAGE P6 F785LP PRE-FLASH=YES 1 70S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6218 PC IMAGE P6 F785LP PRE-FLASH=YES 1 80S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC6362 PC IMAGE P6 F785LP PRE-FLASH=YES 1 100S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC7099 PC IMAGE P6 F785LP PRE-FLASH=YES 1 70S 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC362 PC IMAGE P6 F555W PRE-FLASH=YES 1 100S 1 2 SEQ 1,7 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC4590 PC IMAGE P6 F555W PRE-FLASH=YES 1 100S 1 2 SEQ 2,8 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5904 PC IMAGE P6 F555W PRE-FLASH=YES 1 70S 1 2 SEQ 3,9 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6218 PC IMAGE P6 F555W PRE-FLASH=YES 1 80S 1 2 SEQ 4,10 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC6362 PC IMAGE P6 F555W PRE-FLASH=YES 1 100S 1 2 SEQ 5,11 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC7099 PC IMAGE P6 F555W PRE-FLASH=YES 1 70S 1 1 SEQ 6,12 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3227c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations PC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/OS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 0.25 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GUIDE TOL 0.019" / 1-12 ; CYCLE 1 / 1-12 SEQ 1,7 NO GAP SEQ 2,8 NO GAP SEQ 3,9 NO GAP SEQ 4,10 NO GAP SEQ 5,11 NO GAP SEQ 6,12 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F785LP F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC362 NGC4590 M68 NGC5904 M5 NGC6218 M12 NGC6362 NGC7099 M30 ------------------------------------------------------------------------------------------------------------------------------------