Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2559c Report Date: 09-May-96:17:11 Version: ********** Check-in Date: ********** 1.Proposal Title: THE OLDEST STELLAR POPULATIONS: GLOBULAR CLUSTERS AND THE HISTORY OF THE GALAXY ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR POPULATIONS GO Sub Category GLOBULAR CLUSTERS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. James E. Hesser DOMINION ASTROPHYSICAL OBSER CANADA 604-388-0007 DIRECTOR, DAO ------------------------------------------------------------------------------------ 7. Abstract We propose to use the unique imaging capabilities of the PC to make the next major leap in our understanding of the ages and stellar populations of globular clusters in the Galactic halo. These observations will resolve scientific problems that we have worked on for two decades with ground-based telescopes. The immediate plan is to obtain color-magnitude diagrams and luminosity functions for 3 representative clusters in the far halo; these will allow us to measure relative ages to +/- 1 Gyr and determine their main-sequence mass functions. The ultimate goal is to use globular clusters as cosmological probes: to determine the starting epoch and duration of Galactic halo formation, the mass spectrum of star formation and its dependence upon primordial conditions, and the dynamical evolution of gravitational N-body systems. Major support programs include theoretical modeling of the structure and evolution of stars and star clusters, and the development of photometric algorithms optimized for HST data. ------------------------------------------------------------------------------------ 8. Scientific Key Words: STARS:GLOBULAR CLUSTER, MAIN SEQUENCE; GALACTIC STRUCTURE:HALO; LUMINOSITY FUNCTION, MASS FUNCTION ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 12.60 par: 0 10. Num targs pri: 3 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2559c PI: Dr. James E. Hesser Proposal Title: THE OLDEST STELLAR POPULATIONS: GLOBULAR CLUSTERS AND THE HISTORY OF THE GALAXY ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ P.I. James E. Hesser DOMINION ASTROPHYSICAL CANADA OBSERVATORY Roger A. Bell MARYLAND, UNIVERSITY OF USA Howard E. Bond STSCI USA Gregory G. Fahlman BRITISH COLUMBIA, UNIVERSITY OF CANADA Gilles Fontaine MONTREAL, UNIVERSITY OF CANADA William E. Harris MCMASTER UNIVERSITY CANADA F. David A. Hartwick VICTORIA, UNIVERSITY OF CANADA Robert D. Mcclure DOMINION ASTROPHYSICAL CANADA OBSERVATORY Christopher J. Pritchet VICTORIA, UNIVERSITY OF CANADA Carlton R. Pryor RUTGERS UNIVERSITY USA Harvey B. Richer BRITISH COLUMBIA, UNIVERSITY OF CANADA Don A. Vandenberg VICTORIA, UNIVERSITY OF CANADA Peter B. Stetson DOMINION ASTROPHYSICAL CANADA OBSERVATORY Sidney Van Den Bergh DOMINION ASTROPHYSICAL CANADA OBSERVATORY Francois Wesemael MONTREAL, UNIVERSITY OF CANADA ------------------------------------------------------------------------------------ 2. Scientific Justification. (See original proposal for Scientific Justification) ------------------------------------------------------------------------------------ 3. Description of proposed observations. We will use the PC with the F555W (V) and F791W (I) filters to obtain deep color -magnitude diagrams and luminosity functions for globular clusters in the far outer halo of our galaxy, in order to determine cluster ages and main-sequence mass functions. For the 3 halo globular clusters, NGC 2419, Pal 3, and Pal 4, we will obtain three 2340-sec exposures each in V and I, and two 30-sec exposures in the same filters (the exposure times were chosen to fit within the TAC's time allocation). The target positions, accurate to better than 1", were measured with the GASP system, and were chosen to be as near as possible to the cluster centers while avoiding bright stars. The roll angle for the first exposure on each cluster is arbitrary, but all subsequent exposures should be taken at the same roll. We would like to move the telescope approximately 0.2" between successive exposures so that the same star is not always on the same pixel. The chips should be given the standard pre-flash, and there should be no cosmic-ray split. CLOCKS=YES is requested for the long exposures. The long exposures should be taken after the short exposures, to minimize residual images. The long exposures should reach approximately S/N = 15 at V = 27.4. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. (See original proposal) ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. (See original proposal) Page 3 ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. All exposures should be taken at the same roll angle (or roll angles differing by +/- 90 or 180 degrees), so that we will not lose stars from the corners of the field when combining data from the multiple exposures. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. (See original proposal) ------------------------------------------------------------------------------------ 8. Additional comments or special requests. We request the standard one-year proprietary rights, calculated from the date of the last exposure on each field. ------------------------------------------------------------------------------------ 9. Description of previous HST work. N/A ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). (See original proposal) ------------------------------------------------------------------------------------ 11. Address Information Name: JAMES E. HESSER Category: PI Institution: DOMINION ASTROPHYSICAL OBSERVATOR Address: 5071 W. SAANICH ROAD City: VICTORIA BC V8X 4M6 State: Zip Code: Country: CANADA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2559c [ 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 NGC2419 STAR CLUSTER; GLOBULAR PLATE-ID = 01H9, J2000 1 V = 27.4 CLUSTER; HALO; RA = 07H 38M 14.6S +/- 1", PHOTOMETRY; POPULATION DEC = +38D 50' 49" +/- 1" II ------------------------------------------------------------------------------------------------------------------------------------ 2 PAL3 STAR CLUSTER; GLOBULAR PLATE-ID = 00JL, J2000 1 V = 27.4 CLUSTER; HALO; RA = 10H 05M 31.3S +/- 1", PHOTOMETRY; POPULATION DEC = +00D 04' 58" +/- 1" II ------------------------------------------------------------------------------------------------------------------------------------ 3 PAL4 STAR CLUSTER; GLOBULAR PLATE-ID = 019K, J2000 1 V = 27.4 CLUSTER; HALO; RA = 11H 29M 19.13S +/- 1", PHOTOMETRY; POPULATION DEC = +28D 57' 59.4" +/- 1" II ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2559c [ 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 DEFINE # PC IMAGE ALL F555W CR-SPLIT=NO 1 30S 1 1 GUID TOL 0.020" / SHORTEX PRE-FLASH=YES 1-10 P SAME ORIENT FOR 2- 10 AS 1 POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ POS TARG 0.22, 0.22 ------------------------------------------------------------------------------------------------------------------------------------ 3 ^ ^ ^ ^ ^ F791W ^ ^ ^ ^ POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ POS TARG 0.22, 0.22 ------------------------------------------------------------------------------------------------------------------------------------ 5 DEFINE # PC IMAGE ALL F555W CR-SPLIT=NO 1 2340S 15 1 1 POS TARG 0.0, 0.0 LONGEXP PRE-FLASH=YES CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 6 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ POS TARG 0.22, 0.22 ------------------------------------------------------------------------------------------------------------------------------------ 7 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ POS TARG 0.44, 0.44 ------------------------------------------------------------------------------------------------------------------------------------ 8 ^ ^ ^ ^ ^ F791W ^ ^ ^ ^ ^ POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 9 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ POS TARG 0.22, 0.22 ------------------------------------------------------------------------------------------------------------------------------------ 10 DEFINE # PC IMAGE ALL F791W CR-SPLIT=NO 1 2340S 15 1 1 POS TARG 0.44, LONGEXP PRE-FLASH=YES 0.44 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 11 USE NGC2419 SHORTEX P ------------------------------------------------------------------------------------------------------------------------------------ 12 USE NGC2419 AFTER 11 LONGEXP ------------------------------------------------------------------------------------------------------------------------------------ 13 USE PAL3 SHORTEX P ------------------------------------------------------------------------------------------------------------------------------------ 14 USE PAL3 AFTER 13 LONGEXP ------------------------------------------------------------------------------------------------------------------------------------ 15 USE PAL4 SHORTEX P ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2559c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 16 USE PAL4 AFTER 15 LONGEXP ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2559c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations PC ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ^ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO PRE-FLASH=YES CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 12.60 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category GLOBULAR CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GUID TOL 0.020" / 1-10; SAME ORIENT FOR 2-10 AS 1; POS TARG 0.0, 0.0 POS TARG 0.22, 0.22 POS TARG 0.44, 0.44 AFTER 11 AFTER 13 AFTER 15 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ^ F791W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC2419 PAL3 PAL4 ------------------------------------------------------------------------------------------------------------------------------------