Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5380 Report Date: 18-Jul-95:17:16 Version: ********** Check-in Date: ********** 1.Proposal Title: UV SPECTRAL DISTRIBUTION IN LOW LUMINOSITY ACTIVE GALAXIES - IMAGING: CYCLE 4 MEDIUM ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID QUASARS & AGN GO Sub Category OTHER ACTIVE NUCLEI ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Anuradha P. Koratkar 3470 USA (410) 338-4470 ------------------------------------------------------------------------------------ 7. Abstract Observations of activity in the nuclei of galaxies from the most energetic (QSOs) to the mildly energetic (LINERs) show that many of the properties are similar and the objects might be related to each other. A crucial question that arises is, ``Is the basic mechanism that powers the activity the same in all these galaxies and do the properties of active nuclei just scale with luminosity\?'' Many studies suggest that QSOs and luminous Seyfert nuclei have the same basic energy source. This continuity of properties suggests an extension to still lower luminosities, but there might be a lower limit to the activity (analogous to the mass limit in main sequence stars). Hence, it is important to determine whether Low Luminosity AGNs (LLAGNs; or a certain sub-class of them) are genuinely related to classical AGNs, or whether instead their properties might be due to other physical processes. In this proposal we request FOS and PC observations of 4 LLAGNs (detected with ROSAT) to determine the physical processes responsible for UV radiation in these objects. The results of this analysis will not only help bridge the gap between LLAGNs and normal galaxies, but answer the following question: How similar are the LLAGNs to the higher luminosity AGNs\? More specifically, what is the dominant mechanism for the production of ionizing radiation\? ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 2.94 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5380 PI: Anuradha P. Koratkar Proposal Title: UV SPECTRAL DISTRIBUTION IN LOW LUMINOSITY ACTIVE GALAXIES - IMAGING: CYCLE 4 MEDIUM ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Anuradha P. Koratkar 3470 USA Susana E. Deustua 2460 USA Ian N. Evans 3470 USA Alexei V. Filippenko 1500 USA Timothy M. Heckman 3470 USA Luis C. Ho 1500 USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. We plan to use the WFPC2 PC to observe the objects in our sample using the F218W filter to determine the spatial extent of the nuclear UV continuum source for comparison with X-ray imaging data. Since the spatial resolution of the WFPC2 PC is an order of magnitude better than the ROSAT HRI resolution, the morphology of the UV continuum source will enable us to investigate the central source on much smaller spatial scales than would otherwise be possible. We have selected the F218W filter because of its high UV efficiency and the absence of strong UV emission lines in the filter bandpass. The WFPC2 images will also be used to decide on target acquisition strategies for the subsequent spectra, based on the observed UV morphology of the target. We will use the FOS blue detector with the G160L grating to determine the spectral energy distribution and emission-line properties of the nuclear source. The G160L exposures are designed to provide a S/N ratio of approximately 15:1 per pixel in the continuum at 1800 Angstroms. We will use the WFPC2 PC with the F218W filter to determine the spatial extent of the nuclear UV continuum source in the objects in our sample. The targets should be placed at the PC1 aperture position, with the exposures split 2:1 to maximize our dynamic range given the uncertain UV flux distribution. The F218W science exposures will also be used as EARLY ACQ images for the FOS observations. We currently plan to use a FOS ACQ/BINARY on an offset star that should be visible in each of the WFPC2 images and offset directly to the nucleus. If the WFPC2 images indicate that the nucleus is sufficiently compact, we will instead use ACQ/BINARY to acquire directly the nucleus. If a suitable offset star is not visible on the WFPC2 images, we will modify our acquisition sequence to include a 3x3 peakup on the nucleus using the 0.5 aperture after the ACQ/BINARY on an offset star. We will obtain an FOS ACQ image after offsetting to the target to verify the spacecraft pointing. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. These observations can only be obtained in the satellite ultraviolet. We have obtained all relevant IUE data relating to the nuclei of the objects in this sample. The brightest of the the objects in our sample was observed by IUE, but the S/N is very low. The UV continua of these objects is too faint to obtain adequate S/N using IUE. We have observed the objects in this sample using the ROSAT HRI imager, and have recently been awarded ROSAT PSPC time to obtain X-ray spectra for these targets. We also have high resolution optical imaging data and optical spectra of these objects. It is possible that the blue bump could be a major contributor to the energy budget for these objects. Therefore, HST data in the effectively unobserved UV waveband are critical to understanding the spectral energy distribution for these objects. We have estimated the nuclear continuum flux we expect from the nuclei of these objects from the UV/H-BETA and UV/X-ray luminosity correlations for AGNs. The predicted flux for all of these objects is similar to 1.0E-15 erg/cms^2/s/A, consistent with that determined from the existing NGC 5273 IUE data. We have therefore assumed that the nuclear continuum flux will be present at this level in our exposure time calculations. Since we do not have additional UV flux information for any of the objects in the sample, we have assumed the same exposure times for each object. The WFPC2 exposure times have been chosen so as not to saturate the CCD even in the unlikely event that all of the nuclear flux arises from a point source, and to provide a mean S/N ratio per pixel of approx. 20:1 if the emission is extended 1". The FOS/BL G160L exposures are designed to obtain approximately 250 counts per pixel in the continuum at 1800 Angstroms, and approximately 130 counts per pixel in the continuum at 1400 Angstroms. This signal level is the minimum required to accurately determine the continuum spectral energy distribution and measure the emission lines with reasonable accuracy. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. None. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. None. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. None. Page 4 ------------------------------------------------------------------------------------ 9. Description of previous HST work. 3591 - "Massive Stars in Starburst Galaxies" (Heckman, PI) 3837 - "Sectropolarimetry of Low Red-shift Active Galactic Nuclei: Test of the Quasar Emission Mechanism" (Koratkar, PI) 4302 - "Supernovae and their Local Environment" (Filippenko, PI) 4312 - "Circumstellar Matter around Supernovae" (Filippenko, PI) 4340 - "Origin of Blue Featureless Continuum in Seyfert 2 Nuclei" (Filippenko, PI; Ho, Co-I) 4350 - "FOS Observations of LINER Galaxy Nuclei" (Filippenko & Ho, Co-I) 4364 - "Ultraviolet and Optical Nebular Diagnostics for Photoionization and Shock Heated Emission Line Gas" (Evans PI, Koratkar Co-I) 4370 - "Space-UV Imaging of Nearby Powerful Radio Galaxies" (Heckman, PI) 4967 - "Carbon, Nitrogen, and Oxygen abundances in Nearby Seyfert Galaxies" (Koratkar, PI, Evans Co-I) Except for 4350 none of the above programs are related to this proposal. The main emphasis of 4350 is on measuring emission to determine excitation mechanism and absorption lines to detect hot, young stars. Observations for the program 3837, 4370 have not yet begun. Observations for 3591 are currently in progress. Data for programs 4364, and 4967 have only recently been obtained, and are being analyzed. 2590 and 3507 have been completed and the results are in press and these programs are not mentioned above. Data for others have not yet been obtained. "HST Imaging of the Inner 3 Arcseconds of NGC1068 in the light of [OIII] 5007", Evans, I.N., Ford, H.C., Kinney, A.L., Antonucci, R.R.J., Armus, L. & Caganoff, S., Ap.J.Lett., 369, L31, 1991. "Faint Object Spectrograph Spectroscopy of Resolved Structure in the Nucleus of NGC1068", Caganoff, S., Antonucci, R.R.J., Ford, H.C., Kriss, G.A., Hartig, G., Armus, L., Evans, I.N., Rosenblatt, E., Bohlin, R.C., & Kinney, A.L., Ap.J.Lett., 377, L9, 1991. "Hubble Space Telescope Imaging of the Narrow Line Region of NGC 4151", Evans, I.N., Tsvetanov, Z., Kriss, G.A., Ford, H.C., Caganoff, S., & Koratkar, A.P., Ap. J., in press, 1993. "A Gravitational Lens Candidate Discovered with the Hubble Space Telescope," Maoz, D., Bahcall, J.N., Schneider, D.P., Doxsey, R., Bahcall, N.A., Filippenko, A.V., Goss, W.M., Lahav, O., & Sargent, W.L.W., Ap.J.Lett., 386, L1, 1992. "HST Observations of NGC 4395, the Least Luminous Seyfert 1 Nucleus: Evidence Against the Starburst Hypothesis for Broad-Lined Active Galactic Nuclei," Filippenko, A.V., Ho, L.C., & Sargent, W.L.W., Ap.J.Lett., in press. "NGC 4395: Evidence Against the Starburst Hypothesis for Seyfert 1 Nuclei and QSOs," Filippenko, A.V., Ho, L.C., & Sargent, W.L.W., in 16th Texas Symposium/3rd Symposium on Particles, Strings, and Cosmology, ed. C. Akerlof and M. Srednicki (New York: New York Academy of Sciences), 1993, in press. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). The investigators on this proposal have access to the standard data analysis and research support facilities provided by their home institutions. No special support for this project will be provided by any of the proposers' home institutions. ------------------------------------------------------------------------------------ 11. Address Information Name: ANURADHA P. KORATKAR Category: PI Institution: 3470 Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: (410) 338-4470 Telex (or e-mail): KORATKAR@STSCI.EDU ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5380 [ 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 NGC4278 E,303,312,910,923,924 RA = 12H 20M 06.766S +/- J2000 V = +649 1 V = 16.3 2.0", DEC = +29D 16' 49.27" +/- 2.0", PLATE-ID = 00DJ ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 E,301,312,910,923,924 RA = 12H 42M 52.326S +/- J2000 V = 1 V = 16.3 2.0", +1010 DEC = +13D 15' 25.80" +/- 2.0", PLATE-ID = 00IY ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5033 E,303,312,910,923,924 RA = 13H 13M 27.536S +/- J2000 V = +878 1 V = 16.3 2.0", DEC = +36D 35' 37.12" +/- 2.0", PLATE-ID = 01PR ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5273 E,303,312,910,923,924 RA = 13H 42M 08.354S +/- J2000 V = 1 V = 16.3 2.0", +1054 DEC = +35D 39' 15.32" +/- 2.0", PLATE-ID = 01QW ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5380 [ 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 NGC4278 WFPC2 IMAGE PC1 F218W CR-SPLIT=NO 1 1800S 1 CYCLE 4 / 1-4.0 Comments: EARLY ACQ FOR 5-7 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4639 WFPC2 IMAGE PC1 F218W CR-SPLIT=NO 1 1800S 1 Comments: EARLY ACQ FOR 8-10 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5033 WFPC2 IMAGE PC1 F218W CR-SPLIT=NO 1 1800S 1 Comments: EARLY ACQ FOR 11-13 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5273 WFPC2 IMAGE PC1 F218W CR-SPLIT=NO 1 1800S 1 Comments: EARLY ACQ FOR 14-16 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5380 [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 2.94 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QUASARS & AGN ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category OTHER ACTIVE NUCLEI ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1-4.0; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F218W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC4278 NGC4639 NGC5033 NGC5273 ------------------------------------------------------------------------------------------------------------------------------------