7435( 18) - 09/30/97 09:26 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7435 Version: 18 Check-in Date: 30-Sep-1997 09:23:12 1.Proposal Title: Nuclear kinematics and stellar population gradients in the recent merger remnants NGC 7252 & NGC 3921. ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle GALAXIES GO 7 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: KONRAD KUIJKEN KAPTEYN INSTITUTE CoI: Marijn Franx Kapteyn Institute N ------------------------------------------------------------------------------------ 6. Abstract We propose to study the central kinematics of stellar populations in two recent merger remnants, NGC 7252 and NGC 3921. Ground-based spectra show these galaxies contain centrally concentrated young stellar populations and emission- line gas, indicative of a merger-induced episode of star formation. We have spectrally separated the kinematics of the young (A-star like) and old (metal-line) stars, and interestingly, the kinematic axes of the gas and of the stellar populations are different, suggesting that we are seeing the formation of kinematically-distinct cores. Given some of the unanswered questions surrounding the merger formation scenario in general (why are stellar populations so tightly related to overall structural parameters? Why are kinematically distinct cores so unremarkable photometrically? What drives core properties?), it is therefore of interest to observe the central kinematics and populations with the high spatial resolution offered with STIS, to investigate the relation between merging and core/cusp morphology. These two merger remnants offer us the rare possibility to see the core formation process at work. ------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 2] Observations Description ------------------------ We require two slit orientations per galaxy, along the nuclear major and minor axes (as determined from the WFPC images). The major axis will allow measurement of the rotation curve of the old and young stars as well as velocity dispersion of the older stars, and the minor axis is necessary to check for kinematic misalignments between young and old stars (such as are seen in our groundbased data at radii beyond 1''). Population gradients can also be determined from the spectra, and will yield information about the relation between any pre-existing core structure and the cuspiness of the newly formed stars. We require a signal-to- noise ratio of 20 per spectral bin in order to measure simultaneously the radial velocity of the A-star and K-star lines from the spectrum (with accuracy 0.1 pixel). This velocity accuracy, ca 20km/s, suffices given the relatively high rotation velocities we detect from the ground. In order to join onto our groundbased data at a radius of 1'', where the V-band surface brightness is 17^m/''^2, we require five full-orbit exposures of 2400 seconds. (S/N is 4.2 per lambda- pixel per 0.1'' of slit at 5200Angstrom for a single 2300- second exposure, or 9.4 for a set of five; we will bin the spectra between 0.8'' and 1.2'' to achieve a S/n of 20 at that radius). The central surface brightness is 15^m/''^2, which gives a central S/N of 16.2 per 0.1'' of slit per single exposure. Combining the 10 exposures will allow an accurate central velocity dispersion to be derived. Real Time Justification ----------------------- None. Calibration Justification ------------------------- Additional Comments ------------------- Prelimanary Phase II submission. I am awaiting word from STScI on whether the automatic wavecals will provide 0.1 pixel wavelength scale accuracy, and if not, whether additional wave exposures can be done during occultation of the target. ------------------------------------------------------------------------------------ Data Distribution Media: DAT Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC3921 GALAXY,NUCLEUS,ELLIPTIC RA=11H 51M 6.99S +/- 1",DEC=55D J2000 V = 5838 SURF(V) = 13.5+/-1 AL 4' 43" +/- 1",PLATE-ID=00LK Comments: nucleus position and central surface brightness determined from archive WFPC2 image. 250DN /pix in 30 sec, V band, chip 1). 2 NGC7252 GALAXY,NUCLEUS,ELLIPTIC RA=22H 20M 44.78S +/- 1",DEC=- J2000 V = 4760 SURF(V) = 13+/-1 AL 24D 40' 41.9" +/- 1",PLATE- ID=024S Comments: Nucleus position and central surface brightness from archive WFPC2 image (850 DN /pix in 60 sec, V filter, chip 1). 7435( 18) - 09/30/97 09:26 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 224D TO 234D On Hold Comments: Additional Comments: ALTERNATIVE ORIENT 224D TO 226D ALSO OK SLIT ALIGNED WITH INNER DISK (PA=0D+/-1D) Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC3921 STIS/C ACQ F28X50L MIRROR ACQTYPE=DIFFUSE,CHECKBOX=7, 1 4 S ONBOARD ACQ FOR 10 CD P DIFFUSE-CENTER=GEOMETRIC-CENTER ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC3921 STIS/C ACQ/PEA 52X0.1 MIRROR 1 20 S ONBOARD ACQ FOR 15 CD K ------------------------------------------------------------------------------------------------------------------------------------ 15 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2, 1 2000 S EXPAND POS TARG 0,0.5 CD WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ 25 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 30 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 35 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 47 M EXPAND POS TARG 0,1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 37 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 40 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 45 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 47 M EXPAND POS TARG 0,-0.5 CD ------------------------------------------------------------------------------------------------------------------------------------ 47 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 50 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 55 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 47 M EXPAND POS TARG 0,-1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 57 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S END ORBIT CD ------------------------------------------------------------------------------------------------------------------------------------ 60 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 65 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=1 1 47 M EXPAND CD ------------------------------------------------------------------------------------------------------------------------------------ 67 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ORIENT 83D TO 83D On Hold Comments: Additional Comments: ALTERNATIVE ORIENT 263D TO 263D ALSO OK THIS ORIENTATION COVERS NUCLEUS AND WHITMORE ET AL (AJ 106,1354) SOURCE 45. OFFSET FROM NUCLEUS (ARCSEC): 1.01E,1.31N, SO PA 38D Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7252 STIS/C ACQ F28X50L MIRROR 1 4 S ONBOARD ACQ FOR 10 CD P ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC7252 STIS/C ACQ/PEA 52X0.1 MIRROR 1 20 S ONBOARD ACQ FOR 15 CD K ------------------------------------------------------------------------------------------------------------------------------------ 15 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS2=1,BINAXIS1=2, 1 27 M EXPAND POS TARG 0,0.5 CD WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ 25 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 30 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 35 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 2620 S EXPAND POS TARG 0,1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 37 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 40 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 45 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 2620 S EXPAND POS TARG 0,-0.5 CD ------------------------------------------------------------------------------------------------------------------------------------ 47 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 50 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 55 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 2620 S EXPAND POS TARG 0,-1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 57 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S END ORBIT CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 60 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 65 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=1 1 2620 S EXPAND CD ------------------------------------------------------------------------------------------------------------------------------------ 67 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 8] Visit: 02 Visit Priority: Visit Requirements: ORIENT 134D TO 136D On Hold Comments: Additional Comments: ALTERNATIVE ORIENT 314D TO 316D ALSO OK. SLIT ALIGNED PERPENDICULAR TO INNER DISK. DISK PA IS 0D. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC3921 STIS/C ACQ F28X50L MIRROR ACQTYPE=DIFFUSE,CHECKBOX=7, 1 4 S ONBOARD ACQ FOR 10 CD P DIFFUSE-CENTER=GEOMETRIC-CENTER ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC3921 STIS/C ACQ/PEA 52X0.1 MIRROR 1 20 S ONBOARD ACQ FOR 15 CD K ------------------------------------------------------------------------------------------------------------------------------------ 15 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2, 1 2000 S EXPAND POS TARG 0,0.5 CD WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ 25 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 30 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 35 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 47 M EXPAND POS TARG 0,1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 37 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 40 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 45 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 47 M EXPAND POS TARG 0,-0.5 CD ------------------------------------------------------------------------------------------------------------------------------------ 47 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 50 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 55 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 47 M EXPAND POS TARG 0,-1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 57 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S END ORBIT CD ------------------------------------------------------------------------------------------------------------------------------------ 60 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 9] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 65 NGC3921 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=1 1 47 M EXPAND CD ------------------------------------------------------------------------------------------------------------------------------------ 67 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 10] Visit: 04 Visit Priority: Visit Requirements: ORIENT 4D TO 4D SCHED 70% On Hold Comments: Additional Comments: ALTERNATIVE ORIENT 184D TO 184D ALSO OK. ALTERNATIVE ORIENT 165D TO 165D ALSO OK. ALTERNATIVE ORIENT 345D TO 345D ALSO OK. THIS ORIENTATION COVERS NUCLEUS AND WHITMORE ET AL (AJ 106,1354) SOURCE 50 OR 51. 50:OFFSET FROM NUCLEUS (ARCSEC): 1.84E,-2.08N, SO PA 139D. 51:OFFSET FROM NUCLEUS (ARCSEC): 2.31E,-1.36N, SO PA 120D. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7252 STIS/C ACQ F28X50L MIRROR 1 4 S ONBOARD ACQ FOR 10 CD P ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC7252 STIS/C ACQ/PEA 52X0.1 MIRROR 1 20 S ONBOARD ACQ FOR 15 CD K ------------------------------------------------------------------------------------------------------------------------------------ 15 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2, 1 27 M EXPAND POS TARG 0,0.5 CD WAVECAL=NO ------------------------------------------------------------------------------------------------------------------------------------ 25 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 30 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 35 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 2440 S EXPAND POS TARG 0,1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 37 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 40 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 45 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 2440 S EXPAND POS TARG 0,-0.5 CD ------------------------------------------------------------------------------------------------------------------------------------ 47 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 50 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 55 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=2 1 2440 S EXPAND POS TARG 0,-1.0 CD ------------------------------------------------------------------------------------------------------------------------------------ 57 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S END ORBIT CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 11] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 60 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 65 NGC7252 STIS/C ACCUM 52X0.1 G430L 4300 CR-SPLIT=2,BINAXIS1=1,BINAXIS2=1 1 2440 S EXPAND CD ------------------------------------------------------------------------------------------------------------------------------------ 67 WAVE STIS/C ACCUM 52X0.1 G430L 4300 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 7435( 18) - 09/30/97 09:26 - [ 12] Summary Form for Proposal 7435 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=DIFFUSE CHECKBOX=7 DIFFUSE-CENTER=GEOMETRIC-CENTER WAVECAL=NO BINAXIS2=2 BINAXIS1=1 CR-SPLIT=2 BINAXIS2=1 BINAXIS1=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 224D TO 234D ONBOARD ACQ FOR 10 ONBOARD ACQ FOR 15 EXPAND POS TARG 0,0.5 EXPAND POS TARG 0,1.0 EXPAND POS TARG 0,-0.5 EXPAND POS TARG 0,-1.0 END ORBIT EXPAND ORIENT 83D TO 83D ORIENT 134D TO 136D ORIENT 4D TO 4D SCHED 70% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G430L ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC3921 WAVE NGC7252 ------------------------------------------------------------------------------------------------------------------------------------