Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3551c Report Date: 09-May-96:18:42 Version: ********** Check-in Date: ********** 1.Proposal Title: ELLIPTICALS WITH KINEMATICALLY-DISTINCT NUCLEI ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID GALAXIES & CLUSTERS GO Sub Category NUCLEI/CORES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Garth D Illingworth UCO/LICK OBSERVATORY USA 408-459-2843 ------------------------------------------------------------------------------------ 7. Abstract The discovery by Franx and Illingworth of a kinematically-distinct stellar com- ponent in the nucleus of the giant radio elliptical IC 1459, and the confirma- tion that such components are quite common, has added a valuable diagnostic tool for understanding the structure and the formation of ellipticals. Fifteen examples are now known, from a sample of 77 ellipticals. The angular momenta of the distinct components are anti-parallel, perpendicular, or parallel to the angular momenta of the outer parts. These substantial (10^10 solar masses for IC 1459) components are a valuable diagnostics of the dynamical state of the nuclei of ellipticals. Further study will address their formation by investigating whether these components could be the end result of a 'starburst' event, or of the accretion and settling of a stellar companion, or of the merging of primordial subclumps. We propose to take advantage of the high resolution imaging capability of HST through a PC imaging program of the 7 galaxies that are not part other imaging programs, with the goal of detecting central surface brightness cusps in the central regions of the galaxies with kinematically distinct cores. A comparative study of normal galaxies (observed by other programs) and galaxies with kinematically distinct cores can provide unique information on the formation of these components. These data are an essential complement to an extensive ground-based spectroscopic and CCD imaging survey, and will allow a much better modeling of the spectroscopic data. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.67 par: 0 10. Num targs pri: 7 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3551c PI: Garth D Illingworth Proposal Title: ELLIPTICALS WITH KINEMATICALLY-DISTINCT NUCLEI ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Garth D Illingworth UCO / LICK OBSERVATORY USA Marijn Franx SMITHSONIAN ASTRONOMICAL USA OBSERVATORY ------------------------------------------------------------------------------------ 2. Scientific Justification. Of the fifteen ellipticals with kinematically distinct cores, eight are part of GTO programs, or approved GO programs. Thus we will observe the other seven galaxies. This will result in a doubling of the observed sample of ellipticals with distinct cores. Several of the galaxies are of special interest. IC 1459 because it is one the most extreme examples of a galaxy with a kinematically distinct core. NGC 7626 is remarkable because it has a very irregular rotation curve (Jedrzejewski and Schechter 1988, ApJ (Letters), 330, L87). It is very well possible that the central parts are not fully relaxed. It will be very interesting to see whether HST detects any sharp, high contrast features in this galaxy. NGC 1439 is the intrinsically faintest galaxy in the sample, with the lowest velocity dispersion. NGC 1427 has a rotation curve that is unresolved even at subarcsecond seeing. NGC 5982 is the only galaxy which has a distinct core that has a rotation axis parallel to the major axis. All other systems rotate around the minor axis. The galaxies will be observed with the Planetary Camera. Two exposures of comparable length need to be taken in ``V'' (F555W). It is essential to have two exposures to verify the deconvolution techniques. ------------------------------------------------------------------------------------ 3. Description of proposed observations. The use of the imaging capabilities of HST is a logical and important component of a broadly-based observational program involving ground- based long-slit spectra and ground-based CCD images of ellipticals with kinematically-distinct cores. Both the spectroscopic and the imaging results suggest that these distinct nuclear subcomponents are unresolved from the ground in typical 1-2" seeing. The cores of ellipticals are known to be at best marginally resolved from the ground, with a few notable exceptions (see, e.g., Kormendy, 1985, Ap.J. (Letters), 292, L9). If compact star clusters or black-holes are significant in these cores, the small gains in resolution possible at Hawaii and other sites will not be decisive in establishing the structure of the nuclei on scales <0.2". The results by Lauer et al (1991, ApJ 369, L41) have shown convincingly that HST can do significantly better than any ground-based facilities, if proper deconvolution is applied to the images. The HST PC images will complement the available ground-based multicolor CCD surface photometry by allowing comparison of the core structure and properties with those at larger radii. Furthermore, the early `discovery' spectroscopic observations have been supplemented by a set of higher S/N long-slit spectra taken with the highest practical ground-based spatial resolution (~1" with ~0.3-0.6" pixels) at a variety of position angles. These data have been acquired both in the Northern and Southern hemispheres, at CTIO and Lick. This combination of ground and space data is uniquely powerful. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Seven elliptical galaxies are to be observed with the PC to obtain high S/N, high spatial resolution images suitable for the detection and measurement of a stellar cusps in the nuclei. For optimal image reconstruction we are taking two integrations of comparable length. We take pairs of images to verify the structures that may result from the deconvolution. Cosmic rays will be removed by intercomparison of the pairs of frames. The typical surface brightness of the galaxies cannot be predicted in advance, as it may be quite high if a cusp is present. The dynamic range of the system should be able to accommodate central surface brightnesses ~10 times greater than expected from the ground-based photometry. Extrapolating the observed central surface brightnesses of these galaxies, we expect that the count per pixel in the inner pixels will be of the order of 3000-5000 electrons in 600 sec, or about 1500-2500 in each frame of the CR-SPILT image. The signal will drop to typically a few hundred electrons at r~10". The S/N per pixel will be ~50 in each image (70 for the pair). The ``V'' filter is chosen for this study because its PSF will be well-monitored. We believe that this is important for a good deconvolution. If it were not for this constraint, the F702W filter would be optimal, as it produces a signal a factor of two higher than the F555W filter. If the policy regarding the PSF monitoring changes, we may like to adapt our choice of filter. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. No special scheduling requirements. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. The project is being organised to ensure a thorough but speedy path from acquisition of the data to publication of the papers. Both the Co.I and P.I have extensive experience with handling, processing and analysing two-dimensional CCD image data, having been involved in two major multicolor CCD surface photometry programs that together have assembled the largest set of color profiles for ellipticals available to date, with UBR maps of 59 galaxies (Franx, Illingworth and Heckman, 1989, AJ, 98, 538; and Peletier, Davies, Illingworth, Davis and Cawson, 1990, AJ, 100, 1091). Clearly, the most important task ahead is the deconvolution of the images. The results by Lauer et al (1991, ApJ 369, L41) show that even ``simple'' techniques like Lucy's algorithm provide satisfactory answers. It is clear that as experience grows, other algorithms may prove to be better suited. We are experimenting with a procedure that fits a surface brightness profile directly to the data, by an iterative procedure that convolves the profile with the PSF, determines the residuals from the fit, and adapts the surface brightness profile. This technique can circumvent the double-staged approach where the images are first deconvolved and then fitted. Broadly, the bulk of the data analysis will be done at Lick, with software design, testing and validation being done at CfA, with the modelling and papers being carried out jointly. More detail of the responsibilities of the PI and CoI will be given in the budget justification section. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. No additional requests. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. We have been assigned supplemental time for a similar proposal in Cycle 1 (# 2591). This project was designed to take multicolor images of NGC 4365, NGC 4406, and IC 1459. We have chosen not to reapply to take color images in cycle 2, because it is highly uncertain how well HST can do in that respect. No data has been taken yet, and is unlikely to be taken in Cycle 1. No data has been taken yet, and is unlikely to be taken in Cycle 1. Page 4 ------------------------------------------------------------------------------------ 9. Description of previous HST work. Lick Observatory has a strong foundation for intensive image processing of large HST images. The department has a powerful host SUN 4/280 system with high performance peripherals that is the heart of a network that includes the P.I's workstation. Several staff are available to support the systems and system software development. There is also a pool of ten or more graduate students, some of whom have University Fellowships, who work intensively with optical imaging and spectroscopy. The P.I's UCSC-supplied workstation will host the student workstation. Both workstations will draw upon the departmental resources. S. Faber, an IDT WF/PC team member, is on the Lick faculty, and will be a source of the IDT team's valuable early experience in processing WF/PC data. The P.I also has access to the 3 m and 1 m telescopes on Mt. Hamilton, and to the Keck 10 m when it is in operation in 1993. Dr. Franx has a Hubble Fellowship, which includes summer salary, and some direct research support which will allow him some computing capability. ------------------------------------------------------------------------------------ 11. Address Information Name: GARTH D ILLINGWORTH Category: PI Institution: UCO/ LICK OBSERVATORY Address: UNIVERSITY OF CALIFORNIA City: SANTA CRUZ State: CA Zip Code: 95064 Country: USA Telephone: (408) 459 2843 Telex (or e-mail): 7607936 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3551c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC1427 E,303,910 RA = 03H 42M 19.60S +/- J2000 V = 1 SURF(V) = 16.1 +/- 2 0.15S, +1413 DEC = -35D 23' 35.2" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +1 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC1439 E,303,910 RA = 03H 44M 49.98S +/- J2000 V = 1 SURF(V) = 16.4 +/- 2 0.15S, +1664 DEC = -21D 55' 14.7" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +0.5 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4494 E,303,910 RA = 12H 31M 24.16S +/- J2000 V = 1 SURF(V) = 15.8 +/- 2 0.15S, +1324 DEC = +25D 46' 28.5" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +0.5 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4589 E,303,910 RA = 12H 37M 24.97S +/- J2000 V = 1 SURF(V) = 16.6 +/- 2 0.15S, +1980 DEC = +74D 11' 31.2" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +1 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5982 E,303,910 RA = 15H 38M 39.74S +/- J2000 V = 1 SURF(V) = 16.2 +/- 2 0.15S, +2904 DEC = +59D 21' 21.0" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +0.5 ------------------------------------------------------------------------------------------------------------------------------------ 6 IC1459 E,303,910 RA = 22H 57M 10.49S +/- J2000 V = 1 SURF(V) = 15.2 +/- 2 0.15S, +1691 DEC = -36D 27' 46.3" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +0.5. ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC7626 E,303,910 RA = 23H 20M 42.54S +/- J2000 V = 1 SURF(V) = 16.6 +/- 2 0.15S, +3423 DEC = +08D 13' 01.7" +/- 2" Comments: BETTER FLUXVAL UNCERTAINTY IS -2 TO +0.5 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3551c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IC1459 PC IMAGE PC6 F555W PRE-FLASH=NO 1 500S 80 1 1 CYCLE 2 / 1-7 CR-SPLIT=0.4 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC7626 PC IMAGE PC6 F555W PRE-FLASH=NO 1 810S 70 1 2 CR-SPLIT=0.38 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC1427 PC IMAGE PC6 F555W PRE-FLASH=NO 1 500S 70 1 2 CR-SPLIT=0.4 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC1439 PC IMAGE PC6 F555W PRE-FLASH=NO 1 640S 70 1 3 CR-SPLIT=0.37 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5982 PC IMAGE PC6 F555W PRE-FLASH=NO 1 640S 70 1 3 CR-SPLIT=0.37 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC4494 PC IMAGE PC6 F555W PRE-FLASH=NO 1 500S 70 1 3 CR-SPLIT=0.4 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC4589 PC IMAGE PC6 F555W PRE-FLASH=NO 1 590S 70 1 4 CR-SPLIT=0.4 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3551c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations PC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PRE-FLASH CR-SPLIT ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.67 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category NUCLEI/CORES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 2 / 1-7 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1427 NGC1439 NGC4494 NGC4589 NGC5982 IC1459 NGC7626 ------------------------------------------------------------------------------------------------------------------------------------