8174( 3) - 02/18/99 12:45 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8174 Version: 3 Check-in Date: 18-Feb-1999 12:43:56 1.Proposal Title: Internal Velocity Distribution in Globular Clusters, II ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: William Van Altena Yale University Observatory CoI: Dr. Peter Shelus University of Texas N CoI: Prof. Charles Bailyn Yale University N CoI: Dr. George Benedict University of Texas N CoI: Prof. Gary Da Costa Mount Stromlo Observatory N CoI: Prof. Raynor Duncombe University of Texas N CoI: Prof. Otto Franz Lowell Observatory N CoI: Prof. Laurence Fredrick University of Virginia N CoI: Dr. Terrence Girard Yale University N CoI: Dr. Paul Hemenway University of Rhode Island N CoI: Prof. William Jefferys University of Texas N CoI: Prof. Ivan King University of California N ------------------------------------------------------------------------------------ 5. Abstract We propose to determine the internal velocity distribution of the globular clusters NGC 6205 (M13) and NGC 6656 (M22) in their cores and, for NGC 6656, as a function of distance from the cluster center, and thus also infer its mass distribution. In addition to measuring the velocity dispersion and any anisotropy to 1 km s^-1 for various classes of stars, ( e.g. giants, dwarfs, blue stragglers), we hope to better quantify the suspected rotation (and hence cluster inclination) apparent in both of these clusters' radial velocity data. We will also derive kinematic distances for the two clusters by comparison to existing radial velocity data. These distances would be good to 1-3\ if the radial velocity data were of the expected accuracy of the proper motions. Instead, we will be limited by the radial velocities to 6\ accuracy, which should still have considerable impact on the derived luminosities of the RR Lyrae stars and their role in the cosmological distance scale. The H ST Astrometry Science Team obtaine d GTO first- epoch exposures of the above clusters and three others (NGC 104, NGC 6752, and NGC 7078). The HST AST and its collaborators were granted Cycle 7 GO time to observe these latter three clusters and those observations are currently pending. In this proposal, we are requesting second-epoch exposures under GO time for the remaining two clusters, NGC 6205 and NGC 6656. ------------------------------------------------------------------------------------ 8174( 3) - 02/18/99 12:45 - [ 2] Observations Description ------------------------ The first-epoch exposures were taken with the (aberrated) PC camera using a strategy of a central exposure and then offsetting by ~100 pixels into each quadrant for an additional four exposures in order to derive an accurate differential distortion calibration for each cluster and at each position within the cluster. Three of the exposures were taken in the F555W filter and two in the F785LP filter so that color information would be available for all stars. More intensive astrometric calibration (five more offset exposures) was done on three clusters to obtain even higher accuracy. Two series of exposures of 25 and 100 seconds were made in the core to sample a wide range of magnitude to study equipartition of energy, while one series of exposures of 1000 seconds was taken at five and ten core radii to study the change in the velocity distribution as a function of radius. Similar second-epoch exposures are proposed here. For the second-epoch exposures, we plan to use the av erage of the first-epoch exposures as an "astrometric flat-field" for reducing the second epoch, thus the ~100 pixel offsets will not be required. Instead, the three F555W and two F785LP exposures at each pointing will be 'dithered' with much smaller offsets, the total of five exposures giving us the required 1 mas centering precision. Due to the unfortunate omission of three of the WFPC2 PC chips in the new camera, we will only have one-quarter of each field per exposure. Therefore Small Angle Maneuvers will be used to sample all four quadrants of the orginal WFPC PC. This will require 3 orbits per cluster, per pointing with 26-s exposure times that will "match" the first-epoch exposures (100-s) in the cores. In the off-core images, 200-s exposures are needed to match the first-epoch (1000-s) and it may not be possible to have five dithers for all four old PC fields. If one quadrant is lost, however, it should be possible to recover it to a large extent by combining the larger-pixel but more numerous WF exposures of that quadrant that r esulted from the other three quadrant's PC pointings. Real Time Justification ----------------------- A moderate orientation constraint will be requested to give approximate alignment (pm10^degrees and modulo 90^degrees) with the first-epoch GTO exposures. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8174( 3) - 02/18/99 12:45 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6656 STELLAR CLUSTER, RA=18H 36M 26.76S +/- 0.1", DEC= J2000 V = 22+/-0.5 GLOBULAR CLUSTER -23D 54' 17.38" +/- 0.1" Comments: R.A. and Dec. is desired position of WFPC2 apex, to match first-epoch PC exposure 2 NGC6656-R1 STELLAR CLUSTER, RA=18H 36M 19.73S +/- 0.1", DEC= J2000 V = 22+/-0.5 GLOBULAR CLUSTER -23D 49' 34.17" +/- 0.1" Comments: R.A. and Dec. is desired position of WFPC2 apex, to match first-epoch PC exposure 3 NGC6656-R2 STELLAR CLUSTER, RA=18H 36M 9.81S +/- 0.1", DEC=- J2000 V = 22+/-0.5 GLOBULAR CLUSTER 23D 44' 1.27" +/- 0.1" Comments: R.A. and Dec. is desired position of WFPC2 apex, to match first-epoch PC exposure 4 NGC6205 STELLAR CLUSTER, RA=16H 41M 44.07S +/- 0.1", J2000 V = 22+/-0.5 GLOBULAR CLUSTER DEC=36D 27' 48.17" +/- 0.1" Comments: R.A. and Dec. is desired position of WFPC2 apex, to match first-epoch PC exposure 8174( 3) - 02/18/99 12:45 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 198D TO 208D On Hold Comments: Additional Comments: Orient. req. is to align with first-epoch WFPC1 (PC) images. Modulo 90 degrees is also acceptable. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6205 WFPC2 IMAGE WF3-FIX F555W 5398 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.500, 37.500 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC6205 WFPC2 IMAGE WF3-FIX F785LP 8617 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.520, 37.520 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC6205 WFPC2 IMAGE WF3-FIX F555W 5398 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.500, 2.100 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC6205 WFPC2 IMAGE WF3-FIX F785LP 8617 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.520, 2.120 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC6205 WFPC2 IMAGE WF3-FIX F555W 5398 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 2.100, 37.500 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC6205 WFPC2 IMAGE WF3-FIX F785LP 8617 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 2.120, 37.520 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 8174( 3) - 02/18/99 12:45 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 217D TO 227D On Hold Comments: Additional Comments: Orient. req. is to align with first-epoch WFPC1 (PC) images. Modulo 90 degrees is also acceptable. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6656 WFPC2 IMAGE WF3-FIX F555W 5398 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.500, 37.500 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC6656 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 26 S POS TARG 37.520, 37.520 ------------------------------------------------------------------------------------------------------------------------------------ 22 NGC6656 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 26 S POS TARG 37.581, 37.581 ------------------------------------------------------------------------------------------------------------------------------------ 24 NGC6656 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 26 S SAME POS AS 22 ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC6656 WFPC2 IMAGE WF3-FIX F555W 5398 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.500, 2.100 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC6656 WFPC2 IMAGE WF3-FIX F785LP 8617 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 37.520, 2.120 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC6656 WFPC2 IMAGE WF3-FIX F555W 5398 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 2.100, 37.500 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC6656 WFPC2 IMAGE WF3-FIX F785LP 8617 DITHER-TYPE=BOX,CLOCKS=YES, 1 26 S POS TARG 2.120, 37.520 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 8174( 3) - 02/18/99 12:45 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ORIENT 217D TO 227D On Hold Comments: Additional Comments: Orient. req. is to align with first-epoch WFPC1 (PC) images. Modulo 90 degrees is also acceptable. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.500, 37.500 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.557, 37.557 ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.614, 37.614 ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.671, 37.671 ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.520, 37.520 ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.581, 37.581 ------------------------------------------------------------------------------------------------------------------------------------ 70 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.642, 37.642 ------------------------------------------------------------------------------------------------------------------------------------ 90 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.100, 37.500 ------------------------------------------------------------------------------------------------------------------------------------ 100 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.157, 37.557 ------------------------------------------------------------------------------------------------------------------------------------ 110 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.214, 37.614 ------------------------------------------------------------------------------------------------------------------------------------ 120 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.271, 37.671 ------------------------------------------------------------------------------------------------------------------------------------ 130 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.120, 37.520 ------------------------------------------------------------------------------------------------------------------------------------ 140 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.181, 37.581 ------------------------------------------------------------------------------------------------------------------------------------ 150 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.242, 37.642 ------------------------------------------------------------------------------------------------------------------------------------ 170 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.100, 2.100 ------------------------------------------------------------------------------------------------------------------------------------ 180 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.157, 2.157 ------------------------------------------------------------------------------------------------------------------------------------ 190 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.214, 2.214 ------------------------------------------------------------------------------------------------------------------------------------ 200 NGC6656-R1 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.271, 2.271 ------------------------------------------------------------------------------------------------------------------------------------ 210 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.120, 2.120 ------------------------------------------------------------------------------------------------------------------------------------ 220 NGC6656-R1 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.181, 2.181 ------------------------------------------------------------------------------------------------------------------------------------ 8174( 3) - 02/18/99 12:45 - [ 7] Visit: 04 Visit Priority: Visit Requirements: ORIENT 217D TO 227D On Hold Comments: Additional Comments: Orient. req. is to align with first-epoch WFPC1 (PC) images. Modulo 90 degrees is also acceptable. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.500, 37.500 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.557, 37.557 ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.614, 37.614 ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.671, 37.671 ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.520, 37.520 ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.581, 37.581 ------------------------------------------------------------------------------------------------------------------------------------ 70 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 37.642, 37.642 ------------------------------------------------------------------------------------------------------------------------------------ 90 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.100, 37.500 ------------------------------------------------------------------------------------------------------------------------------------ 100 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.157, 37.557 ------------------------------------------------------------------------------------------------------------------------------------ 110 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.214, 37.614 ------------------------------------------------------------------------------------------------------------------------------------ 120 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.271, 37.671 ------------------------------------------------------------------------------------------------------------------------------------ 130 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.120, 37.520 ------------------------------------------------------------------------------------------------------------------------------------ 140 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.181, 37.581 ------------------------------------------------------------------------------------------------------------------------------------ 150 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.242, 37.642 ------------------------------------------------------------------------------------------------------------------------------------ 170 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.100, 2.100 ------------------------------------------------------------------------------------------------------------------------------------ 180 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.157, 2.157 ------------------------------------------------------------------------------------------------------------------------------------ 190 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.214, 2.214 ------------------------------------------------------------------------------------------------------------------------------------ 200 NGC6656-R2 WFPC2 IMAGE WF3-FIX F555W 5398 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.271, 2.271 ------------------------------------------------------------------------------------------------------------------------------------ 210 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.120, 2.120 ------------------------------------------------------------------------------------------------------------------------------------ 220 NGC6656-R2 WFPC2 IMAGE WF3-FIX F785LP 8617 CLOCKS=YES,CR-SPLIT=NO 1 260 S POS TARG 2.181, 2.181 ------------------------------------------------------------------------------------------------------------------------------------ 8174( 3) - 02/18/99 12:45 - [ 8] Summary Form for Proposal 8174 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WF3-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DITHER-TYPE=BOX CLOCKS=YES CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 198D TO 208D POS TARG 37.500, 37.500 POS TARG 37.520, 37.520 POS TARG 37.500, 2.100 POS TARG 37.520, 2.120 POS TARG 2.100, 37.500 POS TARG 2.120, 37.520 ORIENT 217D TO 227D POS TARG 37.581, 37.581 SAME POS AS 22 POS TARG 37.557, 37.557 POS TARG 37.614, 37.614 POS TARG 37.671, 37.671 POS TARG 37.642, 37.642 POS TARG 2.157, 37.557 POS TARG 2.214, 37.614 POS TARG 2.271, 37.671 POS TARG 2.181, 37.581 POS TARG 2.242, 37.642 POS TARG 2.100, 2.100 POS TARG 2.157, 2.157 POS TARG 2.214, 2.214 POS TARG 2.271, 2.271 POS TARG 2.120, 2.120 POS TARG 2.181, 2.181 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F785LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC6205 NGC6656 NGC6656-R1 NGC6656-R2 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 5398 8617 ------------------------------------------------------------------------------------------------------------------------------------