7468( 6) - 12/09/98 15:10 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7468 Version: 6 Check-in Date: 06-Mar-1998 09:24:58 1.Proposal Title: YOUNG GLOBULAR CLUSTERS IN MERGER REMNANTS -- PART 4 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Francois Schweizer Carnegie Institution of Washington CoI: Brad Whitmore Space Telescope Science Institute N CoI: Bryan Miller Space Telescope Science Institute and N Carnegie-D.T.M. CoI: Michael Fall Space Telescope Science Institute N ------------------------------------------------------------------------------------ 5. Abstract Mergers seem to have played a major role in determining the shapes and dynamics of E and S0 galaxies. A few galactic mergers still occur and offer valuable clues to past evolutionary processes. Young globular star clusters formed during mergers hold promise for age-dating recent and ancient such events, besides helping shed light on the cluster-formation process itself. With young globulars in several ongoing mergers and <~1 Gyr old remnants now well studied (NGC4038/39, MGC3256, NGC3921, and NGC7252), we propose to observe six galaxies ranging from about 1-3 Gyr old candidate merger remnants to bona fide ellipticals. The four chosen merger remnants all show signatures of aging major starbursts and are to be searched for young to intermediate-age globulars, while the two E's are rich in fine structure and show evidence for possessing intermediate-age globulars. The proposed new HST observations, supplemented by archival data, aim at (1) measuring high-accuracy V-I color indices to considerably fainter magnitudes than done before, and (2) determining the luminosity functions of first- and second-generation clusters to 2-3 mag past the peak for old globulars. Dithering and deep observations in V and I form a crucial part of our strategy. This program should yield valuable new information on globular-cluster system formation, the specific cluster frequency, and the possible evolution of the luminosity function from a power law for very young clusters to the Gaussian typical of old globulars. ------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 2] Observations Description ------------------------ For Visit #1, the WFPC2 will be used with filters F555W (``V''; 4 x 700 s, 60 s) and F814W (``I''; 4 x 800 s, 60 s) to image the peculiar elliptical NGC2865, thought to be a relatively recent merger remnant (ripples, post-starburst spectrum, neutral hydrogen). The short exposures are to guarantee unsaturated images of the nuclear region and brightest candidate globular clusters. The exposures will be taken at 2 different positions separated by 0.25" in both X and Y. This corresponds to 5.5 PC pixels and 2.5 WF pixels. This subpixel dithering will improve the resolution while also helping remove hot pixels. The four long exposures per passband will provide very good cosmic-ray removal. The position is centered on the nucleus, determined as best we can from the DSS image. The orientation is chosen so as to cover the ripple ~1' NE and H~I distribution ESE, while avoiding bright stars. For Visit #2, the WFPC2 will be used with filters F555W (``V''; 4 x 1200 s, 40 s) and F814W (``I''; 4 x 1400 s, 40 s) to image the elliptical NGC3610, thought to be a ~3-5 Gyr old merger remnant (ripples and boxiness, bluish, enhanced H-beta absorption). Similar short-exposure and dithering scheme as for Visit #1. The position is centered on the nucleus, as determined from Cycle-4 frames. The orientation is chosen so as to create overlap with Cycle-4 observations (ORIENTed at 290.3D) and to cover the ripple to the east. The Cycle 7 globular-cluster data will be combined with our own Cycle 4 data and with Cycle 6 data in the HST Archives. For Visit #3, the WFPC2 will be used with filters F555W (``V''; 4 x 700 s, 40 s) and F814W (``I''; 4 x 800 s, 40 s) to image the Virgo cluster S0 galaxy NGC4382, thought to be a several Gyr old merger remnant (ripples and X- structure, bluish, and enhanced H-beta absorption). Similar short-exposure and dithering scheme as for Visit #1. The position is centered on the nucleus, determined from the DSS image. The orientation is chosen so as to keep the V~=13.6 star ~0.9' NNE of the nucleus within WF4, while limiting its bleeding to relatively less interesting regions. For Visit #4, the WFPC2 will be used with filters F555W (``V''; 4 x 1100 s, 40 s) and F814W (``I''; 4 x 1300 s, 40 s) to image the elliptical NGC5018, thought to be a several Gyr old merger remnant (ripples and 2 tails, bluish, enhanced H-beta absorption). Similar short-exposure and dithering scheme as for Visit #1. The position is centered on the nucleus, determined from the DSS image. The orientation is chosen so that the most interesting ripple is covered by WF3 or WF2, while the V~=15.1 star ~1' ESE stays in WF3 or WF2 and brighter stars avoid the rim area. To the extent possible, the Cycle 7 globular-cluster data will be combined with Cycle 6 data in the HST Archives. For Visit #5, the WFPC2 will be used with filters F555W (``V''; 4 x 1100 s, 40 s) and F814W (``I''; 4 x 1300 s, 40 s) to image the peculiar S0 galaxy NGC7585, thought to be a several Gyr old merger remnant (ripples and streamers, bluish, and enhanced H-beta). Similar short-exposure and dithering scheme as for Visit #1. The position is centered on the nucleus, determined from the DSS image. The orientation is chosen so as to cover the most interesting ripple east of the nucleus. For Visit #6, the WFPC2 will be used with filters F555W (``V''; 4 x 700 s, 60 s) and F814W (``I''; 4 x 800 s, 60 s) to image the peculiar S0/a galaxy NGC7727, thought to be an ~1-3 Gyr old merger remnant (ripples and tails, bluish, and slightly enhanced H-beta). Similar short-exposure and dithering scheme as for Visit #1. The position is centered on the nucleus, determined from the DSS image. The orientation range is chosen so as to cover some of the most structure-rich regions. Real Time Justification ----------------------- Not applicable. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 3] Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2865 GALAXY, ELLIPTICAL RA=9H 23M 30.26S +/- 0.1S, DEC=- J2000 V = 2611 V = 11.7+/-0.1 23D 9' 41.2" +/- 1.0", PLATE- B-V = 0.91+/-0.01 ID=04A0 Comments: Peculiar E3 galaxy with ripple ~1' NE. 2 NGC3610 GALAXY, ELLIPTICAL RA=11H 18M 25.166S +/- 0.02S, J2000 V = 1787 V = 10.8+/-0.1 DEC=58D 47' 10.83" +/- 0.3", B-V = 0.86+/-0.01 PLATE-ID=01OJ Comments: Elliptical galaxy (E5) with central disk at PA=133D. Center coordinates from Cycle-4 frames. 3 NGC4382 GALAXY, LENTICULAR RA=12H 25M 24.08S +/- 0.1S, J2000 V = 722 V = 9.1+/-0.1 DEC=18D 11' 27.4" +/- 1.0", B-V = 0.89+/-0.01 PLATE-ID=00G0 Comments: Peculiar S0 galaxy in Virgo cluster. Orient so that V~=13.6 star ~0.9' NNE from center stays in WF4. 4 NGC5018 GALAXY, ELLIPTICAL RA=13H 13M 1.03S +/- 0.1S, DEC=- J2000 V = 2794 V = 10.8+/-0.1 19D 31' 6.2" +/- 1.0", PLATE- B-V = 0.92 ID=020Y Comments: Elliptical galaxy (E4) with ripples and tails. Orient so that V~=15.1 star ~1' ESE stays in WF2 or WF3 and brighter stars avoid rim area. 5 NGC7585 GALAXY, LENTICULAR RA=23H 18M 1.41S +/- 0.1S, DEC=- J2000 V = 3447 V = 11.4+/-0.1 4D 39' 2.5" +/- 1.0", PLATE- B-V = 0.90+/-0.01 ID=02NF Comments: Peculiar S0 galaxy. Orient to cover most interesting ripple E of nucleus. 6 NGC7727 GALAXY, LENTICULAR RA=23H 39M 53.72S +/- 0.1S, DEC= J2000 V = 1836 V = 10.6+/-0.1 -12D 17' 34.8" +/- 1.0", PLATE- B-V = 0.91 ID=04I6 Comments: Peculiar S0/a galaxy. Orient to cover some of the structure-rich regions. 7468( 6) - 12/09/98 15:10 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 225D TO 340D On Hold Comments: Additional Comments: Orientation covers ripple ~1' NE and H~I distribution ESE, while avoiding bright stars. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2865 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC2865 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC2865 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 800 S ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC2865 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 800 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC2865 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC2865 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC2865 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 700 S ------------------------------------------------------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 270D TO 330D On Hold Comments: Additional Comments: Orientation creates overlap with Cycle-4 observations (U3 at 290.3D) and covers ripple to the east. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC3610 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 1200 S Comments: Could fit in 1300 sec, but prefer 1200 sec. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC3610 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 1200 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC3610 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC3610 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 1 40 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC3610 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 1400 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC3610 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 1400 S ------------------------------------------------------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 110D TO 170D On Hold Comments: Additional Comments: Orientation keeps 13.6 mag star in WF4 and bleeding into less interesting regions. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4382 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S GS ACQ SCENARIO SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4382 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 1 40 S ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4382 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 800 S Comments: Could fit in 900 sec, but prefer 800 sec. ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4382 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 800 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4382 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC4382 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC4382 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 700 S ------------------------------------------------------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 8] Visit: 04 Visit Priority: Visit Requirements: ORIENT 290D TO 25D On Hold Comments: Additional Comments: Orientation keeps V=15.1 mag star ~1' ENE in WF2 or WF3 and puts most interesting ripple in WF3 or WF2. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5018 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 1100 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5018 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 1100 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5018 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5018 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 1 40 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5018 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 1300 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC5018 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 9] Visit: 05 Visit Priority: Visit Requirements: ORIENT 150D TO 335D On Hold Comments: Additional Comments: Orientation covers ripple east of nucleus. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC7585 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 1100 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC7585 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 1100 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC7585 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 40 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC7585 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 1 40 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7585 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 1300 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC7585 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 10] Visit: 06 Visit Priority: Visit Requirements: ORIENT 80D TO 280D On Hold Comments: Additional Comments: Orientation covers some of the most structure-rich regions. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC7727 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC7727 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC7727 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 800 S ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC7727 WFPC2 IMAGE PC1-FIX F814W CR-SPLIT=NO 2 800 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7727 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC7727 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 1 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC7727 WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 700 S ------------------------------------------------------------------------------------------------------------------------------------ 7468( 6) - 12/09/98 15:10 - [ 11] Summary Form for Proposal 7468 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 225D TO 340D POS TARG 0.25, 0.25 ORIENT 270D TO 330D ORIENT 110D TO 170D GS ACQ SCENARIO SINGLE ORIENT 290D TO 25D ORIENT 150D TO 335D ORIENT 80D TO 280D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC2865 NGC3610 NGC4382 NGC5018 NGC7585 NGC7727 ------------------------------------------------------------------------------------------------------------------------------------