5920( 6) - 03/06/96 18:07 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5920 Version: 6 Check-in Date: 06-Mar-1996 18:02:36 1.Proposal Title: Extragalactic Globular Cluster Systems ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Galaxies & Clusters GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Jean Brodie Lick Observatory, University of California CoI: John Huchra Harvard-Smithsonian Center for N Astrophysics ------------------------------------------------------------------------------------ 6. Abstract We propose to use WFPC2 imaging data to compile catalogues of globular clusters for 3 galaxies: NGC 4472, the brightest galaxy in the Virgo cluster; NGC 5846, an elliptical at the center of a poor X-ray group of galaxies and NGC 4565, an edge -on spiral galaxy. Luminosity functions will be derived which should be complete down to 27th mag. in V. The luminosity functions will be used to investigate the usefulness of globular clusters as distance indicators. Cluster colors and color gradients will be compared to the color distribution of the underlying galaxy. Surface density profiles will be compared with each other and with the underlying starlight. A major objective is to obtain accurate identifications of globular clusters for follow-up spectroscopy with the Keck telescope for abundance and kinematic studies. Spectroscopy should be feasible down to 24th magnitude which will allow the most complete study to date of extragalactic systems beyond the Local Group. For the first time elliptical galaxies' cluster systems will be compared in detail and Local Group spirals can be compared with similar galaxies at distances greater than 3 Mpc. A systematic survey of the properties of globular cluster systems as a function of parent galaxy type and environment would be an important step toward a better understanding of galaxy formation and evolution. NOTE: NGC 4365 has been substituted for NGC 4565 due to duplications, and NGC 4472 nucleus has been dropped for the same reason. No off-nuclear positions are being done for NGC 4365. ------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 2] Observations Description ------------------------ We propose to obtain images in three positions stepping across each galaxy so as to include the nuclear region and regions on either side of the nucleus. We wish to observe in three filters (450W, 555W and 814W) at each postion to obtain color information and construct color-color diagrams. Using information from Tables 2.2, 6.1 and 6.2 in the WFPC2 Instrument Handbook (globular clusters are almost unresolved at the distance of Virgo) we calculate that, for a globular cluster spectral energy distribution, we need one orbit per galaxy position in the I filter, 1.5 orbits per galaxy position in the B filter and 0.5 orbit per galaxy position in the V filter to obtain comparable S/N in each filter. Although B observations are somewhat time-intensive, (B-I) colors will provide the best indication of metallicity (and the best cluster discrimination will be in the BVI plane) because of the long wavelength baseline and blue sensitivity. Because 555W is so efficient for globulars it costs only an extra half orbit (to be combined with the half-orbit in B) to obtain the important color-color information (we are avoiding control field observations by maximizing background galaxy rejection based on colors). Because of roll-angle considerations the filter sequence should be obtained consecutively at each galaxy position. One orbit will give 2500-3500 seconds of open shutter time for these low ecliptic latitude targets with CR splitting. We need to achieve ~ 15\\ 26th V magnitude to obtain colors accurate enough for cluster discrimination. 3000 seconds in the 814W filter will yield a S/N ~ 8 at that magnitude. We will also place the PC on the galactic nucleus to maximize spatial resolution in the highest background surface brightness regions of the parent galaxies. Real Time Justification ----------------------- None. All three galaxies are well-placed in Declination for follow up spectroscopic obseVations with the Keck telescope. We will use the coordinate list developed from the HST images to define the subsamples for brighter (V<=24) clusters to be spectroscopically studied for abundance studies and dynamical mass determinations of each galaxy's halo. Keck time has been allocated to us at the end of 1994 for our Extragalactic Globular Clusters program and we will be studying clusters in M81 and NGC 1275. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4365 Galaxy,Elliptical RA=12H 21M 55.425S +/- 0.3S, 1950.0 V= +1240 V = 10.6 DEC=+07D 35' 40.26" +/- 5" B-V = 0.96 Comments: Correct this for SURF(V) etc. 2 NGC4472NORTH Galaxy,Elliptical RA=12H 27M 14.4S +/- 0.3S, 1950.0 V=+997 V = 9.0 DEC=+08D 18' 52.0" +/- 5" B-V = 0.8 Comments: Correct this for SURF(V). 3 NGC4472SOUTH Galaxy,Elliptical RA=12H 27M 14.4S +/- 0.3S, 1950.0 V=+997 V = 9.0 DEC=+08D 13' 47.0" +/- 5" B-V = 0.8 Comments: Correct this for SURF(V) etc. 4 NGC5846 Galaxy,Elliptical RA=15H 03M 56.912S +/- 0.3S, 1950.0 V= +997 V = 11.0 DEC=+01D 47' 52.35" +/- 3" B-V = 0.8 Comments: Correct this for SURF(V) etc. 5 NGC5846NORTH Galaxy,Elliptical RA=15H 03M 56.912S +/- 0.3S, 1950.0 V=+997 V = 11.0 DEC=+01D 49' 23.0" +/- 3" B-V = 0.8 Comments: Correct this for SURF(V). 6 NGC5846SOUTH Galaxy,Elliptical RA=15H 03M 56.912S +/- 0.3S, 1950.0 V=+997 V = 11.0 DEC=+01D 45' 30.0" +/- 3" B-V = 0.8 Comments: Correct this for SURF(V) etc. 5920( 6) - 03/06/96 18:07 - [ 4] Visit: 01 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: Nucleus of NGC 4365. All exposures centered on PC1, and all exposures in this visit implicitly at SAME ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4365 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S Comments: Exposures 1 and 2 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4365 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT POS TARG +0.506,+0.506 Comments: Two exposures of NGC4365 nucleus, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F555W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4365 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S SAME POS AS 1 Comments: Exposures 3 and 4 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4365 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT POS TARG +0.506,+0.506 SAME POS AS 2 Comments: Two exposures of NGC4365 nucleus, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F814W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 5] Visit: 02 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: North of NGC 4472. All exposures centered on PC1, and all exposures in this visit implicitly at SAME ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4472NORT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S H Comments: Exposures 1 and 2 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4472NORT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 Comments: Two exposures N of NGC4472, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F555W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4472NORT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S SAME POS AS 1 H Comments: Exposures 3 and 4 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4472NORT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 SAME POS AS 2 Comments: Two exposures offset N of N4472, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F814W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 6] Visit: 03 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: South of NGC 4472. All exposures centered on PC1, and all exposures in this visit implicitly at SAME ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4472SOUT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S H Comments: Exposures 1 and 2 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4472SOUT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 Comments: Two exposures S of NGC4472, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F555W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4472SOUT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S SAME POS AS 1 H Comments: Exposures 3 and 4 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4472SOUT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 SAME POS AS 2 Comments: Two exposures S of NGC4472, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F814W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 7] Visit: 04 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: NGC5846 nucleus. All exposures centered on PC1, and all exposures in this visit implicitly at SAME ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5846 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S Comments: Exposures 1 and 2 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5846 WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT POS TARG +0.506,+0.506 Comments: Two exposures of NGC5846 nucleus, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F555W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5846 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S SAME POS AS 1 Comments: Exposures 3 and 4 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5846 WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT POS TARG +0.506,+0.506 SAME POS AS 2 Comments: Two exposures of NGC5846 nucleus, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F814W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 8] Visit: 05 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: North of NGC5846. All exposures centered on PC1, and all exposures in this visit implicitly at SAME ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5846NORT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S H Comments: Exposures 1 and 2 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5846NORT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 Comments: Two exposures N of N5846, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F555W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5846NORT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S SAME POS AS 1 H Comments: Exposures 3 and 4 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5846NORT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 SAME POS AS 2 Comments: Two exposures N of NGC5846 , with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F814W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 9] Visit: 06 Visit Requirements: PCS MODE Fine On Hold Comments: Additional Comments: South of NGC 5846. All exposures centered on PC1, and all exposures in this visit implicitly at SAME ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5846SOUT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S H Comments: Exposures 1 and 2 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5846SOUT WFPC2 IMAGE PC1 F555W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 Comments: Two exposures S of NGC5846, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F555W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5846SOUT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S SAME POS AS 1 H Comments: Exposures 3 and 4 will be aligned in data reduction for cosmic ray rejection. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5846SOUT WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT H POS TARG +0.506,+0.506 SAME POS AS 2 Comments: Two exposures S of NGC5846, with the first fixed at 900S and the second allowed to range between 700S and 2400S. The second exposure is also shifted by POS TARG value. POS TARG 0.506 = 11 PC pixels & 5 WFC pixels. Shift is in both x & y. These are the F814W exposures. ------------------------------------------------------------------------------------------------------------------------------------ 5920( 6) - 03/06/96 18:07 - [ 10] Summary Form for Proposal 5920 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Galaxies & Clusters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE Fine EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT POS TARG +0.506,+0.506 SAME POS AS 1 EXPAND MIN DUR 700S MAX DUR 2400S END ORBIT POS TARG +0.506,+0.506 SAME POS AS 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC4365 NGC4472NORTH NGC4472SOUTH NGC5846 NGC5846NORTH NGC5846SOUTH ------------------------------------------------------------------------------------------------------------------------------------