Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 1279c Report Date: 09-May-96:16:25 Version: ********** Check-in Date: ********** 1.Proposal Title: STRUCTURE OF GLOBULAR CLUSTERS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR POPULATIONS GTO/OS Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Ivan R. King UC, BERKELEY USA (415) 642-2206 ------------------------------------------------------------------------------------ 7. Abstract Four contrasting clusters are studied, to elucidate the differences in their dynamics. Omega Centauri and 47 Tucanae are normal clusters but differ in relaxation time by a factor of 30; they should show interesting differences of structure due to differences in anistropy and equipartition. NGC 6624 has a collapsed core, which has never been resolved. NGC 6752 is a concentrated cluster with a small distance modulus and can be studied quite faint. Each cluster is observed in B and V at the center and at 1 and 3 core radii; ground-based data will be secured to carry the distributions farther out. The distributions of all types of stars should be delineated, down to and including red dwarfs and white dwarfs. Far-UV exposures are made at the centers of M15 and NGC 6624, to search for possible counterparts to the X-ray sources, and in the NGC 6752, to determine the temperatures of the BHB stars. Simultaneous exposures are made in V and I with the WFC, to gain further structural information. ------------------------------------------------------------------------------------ 8. Scientific Key Words: GLOBULAR CLUSTERS -- DYNAMICS -- LUMINOSITY FUNCTION ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 11.00 par: 0 10. Num targs pri: 18 par: 0 ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 1279c PI: Ivan R. King Proposal Title: STRUCTURE OF GLOBULAR CLUSTERS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Ivan R. King UC, BERKELEY USA F. Duccio Macchetto ESA, SPACE TELESCOPE SCIENCE USA X INSTITUTE S. Djorgovski CENTER FOR ASTROPHYSICS USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. On each of 3 fields, in each of 4 clusters: f/96, F480LP, 1500 s (par. WFC, F555W) f/96, F430W, 1500 s (par. WFC, F785LP) In addition, NGC 6752, f/48, F175W, 300 s (par. WFC, F157W) NGC 6624, f/288, F175W, 1500 s (par. WFC, F785LP) M15, f/288, F175W, 1200 s (par. WFC, F785LP) Cycle 0: Exp. 24-26 Cycle 1: TBD ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. resolution, UV ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. To be done at UC Berkeley Astronomy VAX. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Relative roll angles specified for each exposure. These ST observations are to be supplemented by ground-based CCD exposures in the outer parts of the clusters; many exposures will be stacked, in order to reach about the same limiting magnitude. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). VAX, S/W, offices, postdoc, Ra's ------------------------------------------------------------------------------------ 12. Roll angles are specified in such a way as to place WFC on same field for all exposures made on a cluster. ------------------------------------------------------------------------------------ 13. Exposures at various radial distances will allow a study of the dynamics of the clusters. Color-magnitude arrays including faint red dwarfs and white dwarfs. The faint end of the BHB in NGC 6752 will be examined. The centers of M15 and NGC 6624 will be examined in the UV for a possible identification of the X-ray sources. ------------------------------------------------------------------------------------ 11. Address Information Name: IVAN R. KING Category: PI Institution: UNIVERSITY OF CALIFORNIA Address: ASTRONOMY DEPARTMENT City: BERKELEY State: CA Zip Code: 94720 Country: USA Telephone: (415) 642-2206 Telex (or e-mail): 820181 UCB AST RAL ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 1279c [ 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 NGC5139 GLOBULAR CLUSTER RA = 13H 23M 45.8S +/- 0.1S, 1950 OMEGA CEN DEC = -47D 13' 03" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1279c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC5139 FOC/96 IMAGE 512X102 F480LP 1 3600S 1 ORIENT 30.0D +/- 4 60D CYCLE 0 GROUP 17-18 NO GAP Comments: READ OUT ONCE PER ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 18 NGC5139 FOC/96 IMAGE 512X102 F430W 1 3600S 1 SAME ORIENT FOR 18 4 AS 17 CYCLE 0 SAME POS FOR 18 AS 17 Comments: READ OUT ONCE PER ORBIT ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 1279c [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOC/96 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/OS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 11.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 30.0D +/-60D; CYCLE 0; GROUP 17-18 NO GAP SAME ORIENT FOR 18 AS 17; CYCLE 0; SAME POS FOR 18 AS 17 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F480LP F430W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC5139 OMEGA CEN ------------------------------------------------------------------------------------------------------------------------------------