6731( 24) - 10/21/98 08:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6731 Version: 24 Check-in Date: 21-Oct-1998 08:57:21 1.Proposal Title: Exploring PN Production as a Probe of Elliptical Galaxy Stellar Populations ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 6 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Robin Ciardullo Pennsylvania State University CoI: John Feldmeier The Pennsylvania State University N ------------------------------------------------------------------------------------ 5. Abstract In addition to being an excellent distance indicator, the O III Lambda 5007 planetary nebula luminosity function (PNLF) is potentially a powerful probe of stellar population. Values for the production rate of bright PN vary by almost an order of magnitude between different galaxies: galaxies with bright absolute magnitudes, strong Mg_2 indices, and large UV upturns are systematically deficient in bright planetary nebulae. This behavior has been cited as support for models of non- traditional post-asymptotic branch evolution ( i.e., the post- early-AGB, and AGB-manque scenarios) in metal-rich systems, and it gives us a tool with which to examine the population of nearby elliptical galaxies. There is, however, one problem in associating the planetary nebula production rate with UV flux or Mg_2 index. Because of crowding and signal-to-noise considerations, groundbased measurements of the PNLF are confined to the outer parts of galaxies, whereas absorption line spectroscopy and UV photometry are restricted to the bright inner regions. We propose to use the Planetary Camera of the Hubble Space Telescope to measure the O III planetary nebula luminosity function in the centers of two nearby ellipticals. These data will quantitatively calibrate the correlations between PN production, UV flux, and the spectroscopic indices of Mg, Fe, and H Beta, allowing PN to be used as a tool for population studies. ------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 2] Observations Description ------------------------ We wish to measuring the planetary nebula luminosity function for two galaxies: NGC 3379 and NGC 4278. The technique for doing this involves taking on-band/off -band images in O III Lambda 5007. The on-band filter is F502N, which has a central wavelength of 5013 Angstrom and is 27 Angstrom wide; the off-band filter is F547M, which is 486 Angstrom wide. The recessional velocities of NGC 3379 and NGC 4278 are 920 and 649 km-s^-1, respectively, so both galaxies fall within the velocity range of the F502N filter. To estimate the exposure time needed to sample the top ~ 1 mag of the PNLF, we begin by noting that the apparent distance modulus of both galaxies is (m-M) = 30.0 (Ciardullo, Jacoby & Ford 1989; Jacoby, Ciardullo, & Harris 1995). Since the PNLF cutoff magnitude is M^* ~ -4.5, this implies that we must reach m_5007 ~ 26.5, where m_5007 is related to monochromatic flux by m_5007 = -2.5log F_5007 - 13.74 Using the F502N filter specifications in the WFPC2 Instrument Handbook (1995), the exposure times necessary to do this with the Planetary Camera at a location 1" from the galaxies' centers is 2.6 hr. This number assumes a signal-to-noise of 10 is required to obtain a statistically complete PN sample (Ciardullo Etal 1987; Hui Etal 1993). Based on their surface brightness profiles, we can expect to find between 10 and 50 PN in the central 15" of NGC 4278 and between 15 and 75 PN in the same region of NGC 3379, depending on the value of alpha_2.5. Real Time Justification ----------------------- None The outer regions of the proposed galaxies have already been surveyed from planetary nebulae. The data for NGC 3379 is published; a paper describing the results for NGC 4278 has been submitted to the Ap. J. Calibration Justification ------------------------- Additional Comments ------------------- If possible, we would like our exposures oriented so that we can link previous ground-based planetary nebulae measurements with the new HST measurements of the cores. This will allow us to put both data on common photometric and astrometric systems. ------------------------------------------------------------------------------------ Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC3379-NUC GALAXY, ELLIPTICAL RA=10H 45M 11S +/- 2.5", DEC=12D B1950 V = 920 V = 9.4+/-0.1 50' 48" +/- 2.5" B-V = 1.0+/-0.1 2 NGC4278-NUC GALAXY, ELLIPTICAL RA=12H 17M 36.20S +/- 0.025S, B1950 V = 649 V = 10.1+/-0.1 DEC=29D 33' 29.0" +/- 0.375" B-V = 1.0+/-0.1 6731( 24) - 10/21/98 08:58 - [ 4] Visit: 01 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC3379-NUC WFPC2 IMAGE PC1 F547M 5 120 S MAX DUR 100% ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC3379-NUC WFPC2 IMAGE PC1 F502N CR-SPLIT=0.0 1 20 M MAX DUR 150% NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC3379-NUC WFPC2 IMAGE PC1 F502N 2 82 M MAX DUR 150% ------------------------------------------------------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 315D TO 90D On Hold Comments: Additional Comments: Visits 2-6 are intended to be observed together with the identical roll angle. The splitting in visits is to force a Guide Star reacquistion after each orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 NGC4278-NUC WFPC2 IMAGE PC1 F547M 5 120 S MAX DUR 100% GS ACQ SCENARIO SINGLE Comments: 16-Apr-98 I.Dashevsky (PC): include new special requirement GS ACQ SCENARIO ONEB1RE, replacing the obsolete method of manual merge in Trans for requesting non standard processing of a proposal. ------------------------------------------------------------------------------------------------------------------------------------ 22 NGC4278-NUC WFPC2 IMAGE PC1 F502N CR-SPLIT=0.0 1 20 M MAX DUR 150% ------------------------------------------------------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 6] Visit: 03 Visit Priority: Visit Requirements: SAME ORIENT AS 2 On Hold Comments: Additional Comments: Visits 2-6 are intended to be observed together with the identical roll angle. The splitting in visits is to force a Guide Star reacquistion after each orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 NGC4278-NUC WFPC2 IMAGE PC1 F502N CR-SPLIT=0.0 1 2600 S MAX DUR 150% GS ACQ SCENARIO SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 7] Visit: 04 Visit Priority: Visit Requirements: SAME ORIENT AS 2 On Hold Comments: Additional Comments: Visits 2-6 are intended to be observed together with the identical roll angle. The splitting in visits is to force a Guide Star reacquistion after each orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 NGC4278-NUC WFPC2 IMAGE PC1 F502N CR-SPLIT=0.0 1 2600 S MAX DUR 150% GS ACQ SCENARIO SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 8] Visit: 05 Visit Priority: Visit Requirements: SAME ORIENT AS 2 On Hold Comments: Additional Comments: Visits 2-6 are intended to be observed together with the identical roll angle. The splitting in visits is to force a Guide Star reacquistion after each orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 51 NGC4278-NUC WFPC2 IMAGE PC1 F502N CR-SPLIT=0.0 1 2600 S MAX DUR 150% GS ACQ SCENARIO SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 9] Visit: 06 Visit Priority: Visit Requirements: SAME ORIENT AS 2 On Hold Comments: Additional Comments: Visits 2-6 are intended to be observed together with the identical roll angle. The splitting in visits is to force a Guide Star reacquistion after each orbit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 61 NGC4278-NUC WFPC2 IMAGE PC1 F502N CR-SPLIT=0.0 1 2600 S MAX DUR 150% GS ACQ SCENARIO SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 6731( 24) - 10/21/98 08:58 - [ 10] Summary Form for Proposal 6731 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements MAX DUR 100% MAX DUR 150% NO SPLIT MAX DUR 150% ORIENT 315D TO 90D MAX DUR 100% GS ACQ SCENARIO SINGLE SAME ORIENT AS 2 MAX DUR 150% GS ACQ SCENARIO SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F547M F502N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC3379-NUC NGC4278-NUC ------------------------------------------------------------------------------------------------------------------------------------