! File: 4340C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:22:28:32 coverpage: title_1: THE ORIGIN OF THE BLUE FEATURELESS CONTINUUM IN SEYFERT 2 NUCLEI: title_2: CYCLE3MEDIUM sci_cat: QUASARS & AGN sci_subcat: SEYFERTS proposal_for: GO pi_title: PROF. pi_fname: ALEXEI pi_mi: V. pi_lname: FILIPPENKO pi_inst: UC-BERKELEY pi_country: USA hours_pri: 2.45 num_pri: 1 foc: Y fos: Y funds_length: 12 off_fname: MARION off_mi: B. off_lname: LENTZ off_title: CONT/GRANTS OFFICER off_inst: 1500 off_addr_1: SPONSORED PROJECTS OFFICE off_addr_2: 336 SPROUL HALL off_addr_3: UNIVERSITY OF CALIFORNIA off_city: BERKELEY off_state: CA off_zip: 94720 off_country: USA off_phone: 510-642-8120 ! end of coverpage abstract: line_1: Recent spectropolarimetric studies of Seyfert 2 nuclei have shown that NGC line_2: 4922B has very low polarization, despite having a rather prominent blue line_3: featureless continuum (BFC). Broad permitted lines also appear to be absent, line_4: both in direct and reflected light. These observed characteristics conflict line_5: with the predictions of simple Seyfert unified models, which assume that the line_6: viewing angle is the only parameter that determines whether the object appears line_7: as a Seyfert 1 or a Seyfert 2 nucleus. If all Seyfert 2s behave like the line_8: prototypical NGC 1068, it is expected that the BFC should be polarized at least line_9: a few percent and that broad lines be present in polarized light. A possible line_10: explanation for NGC 4922B is that the classical broad-line region does not line_11: exist in this object. We should be able to test this by examining the line line_12: profiles of Ly-alpha, C IV, and Mg II. If this object does indeed harbor a line_13: hidden Seyfert 1 nucleus, we should also be able to detect broad Fe II emission line_14: in the UV. Another possibility is that the BFC originates from a population of line_15: hot stars. Much evidence has recently been accumulated that hot stars may play line_16: a significant role in Seyfert 2 nuclei. If so, then FOS spectra should reveal line_17: stellar absorption features (e.g., C IV, Si IV), and FOC images should appear line_18: extended. The shape of the UV continuum will also be useful in discriminating line_19: between a stellar or an AGN ionizing source. We believe that this study has line_20: important implications for the Seyfert unified model. ! ! end of abstract general_form_proposers: lname: FILIPPENKO fname: ALEXEI title: PI mi: V. inst: UC-BERKELEY country: USA ! lname: HO fname: LUIS mi: C. inst: UC-BERKELEY country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We will observe the Seyfert 2 nucleus of NGC 4922B. Our main goals line_2: for the spectroscopy are to detect faint broad wings in the profiles line_3: of permitted emission lines (C IV 1549, Mg II 2800, UV Fe II blends), and to line_4: determine whether the blue continuum in the nucleus is truly featureless. line_5: Thus, we require spectra having good S/N ratio and modest resolution over the line_6: entire accessible UV wavelength range. We will connect the red end of the UV line_7: spectrum (around 3150 A) with our optical spectra, obtained at ground-based line_8: observatories. Three HST grating settings are needed, as follows: line_9: (1) FOS, G130H grating, 1150-1608 A, 1.0 A/diode, blue digicon. line_10: (2) FOS, G190H grating, 1573-2323 A, 1.5 A/diode, red digicon. line_11: (3) FOS, G270H grating, 2227-3306 A, 2.1 A/diode, red digicon. line_12: The FOS spectra will be obtained through the 1.0" circular aperture, since line_13: the 4.3" square aperture gives rise to broad wings in narrow lines. line_14: Note that NGC 7672 is deleted from the program, due to insufficient HST time. line_15: The goal of the direct imaging is to examine the morphology of the UV line_16: continuous emission. Imaging in the UV is best accomplished with the FOC. The line_17: composite IUE spectrum of NGC 1068 published by Snijders et al. (1986), line_18: together with the FOC/96 filter transmission curves shown in Figure 12 line_19: of the FOC Handbook, suggest that the optimal filter is F210M, but there line_20: could be a significant red leak. This leak will be eliminated with the F210M + line_21: F220W combination. The UV morphology will be compared with the red morphology line_22: (F600M). We will use the FOC/96 with a 512 X 512 pixel format, a 25 X 25 micron line_23: square pixel size (0.022" X 0.022" pixels), and a 11" X 11" FOV. ! question: 4 section: 1 line_1: A substantial fraction of the light in Seyfert 2 nuclei comes from old stars line_2: of the host galaxy (Koski 1978). Thus, the near-UV to optical spectral region line_3: is heavily contaminated by starlight. The two main objectives of our proposed line_4: study of NGC 4922B are (1) to search for broad permitted lines in the line_5: emission-line spectrum, and (2) to try to identify a hot star population line_6: by searching for stellar absorption lines, studying the continuum shape, and line_7: looking for extended emission in two-dimensional images. line_8: While searching for broad H-alpha in low-luminosity AGNs by subtraction line_9: of "template" galaxies is sometimes feasible (Filippenko and Sargent 1985), it line_10: becomes increasingly difficult for objects whose active nuclei are very faint line_11: relative to the underlying starlight. Since the contamination from old stars line_12: is much smaller in the UV than in the optical, we expect the weak, broad line_13: permitted lines, if they are present, to be much more easily discernible. For line_14: the same reason, the UV is a more suitable region to study the shape of the line_15: ionizing continuum. Furthermore, the UV Fe II multiplets are expected to be line_16: 10 to 15 times stronger than their optical counterparts. Probably the most line_17: important reason to look in the UV, however, is that this region contains line_18: distinctive absorption features of hot stars (e.g., C IV 1549, Si IV 1400), line_19: unlike the optical or near-infrared region. line_20: The necessity for HST's imaging capabilities is also obvious. We want to line_21: see whether the blue featureless continuum is spatially resolved on scales line_22: smaller than 1", and we would like to determine the morphology of any line_23: resolved continuous emission; comparisons with the red image will be made. ! question: 4 section: 2 line_1: At optical wavelengths, the continuum can be represented roughly as a power line_2: law: f_nu proportional to nu**-1.5). Extrapolating the observed continuum at line_3: 5500 A (f_nu = 1.5 mJy) down to UV wavelengths, we predict that at 1400 A, line_4: 1700 A, and 2300 A the flux density is 0.19 mJy, 0.26 mJy, and 0.41 mJy, line_5: respectively. However, E(B-V) = 0.026 mag, so the UV extinction is about 0.2 line_6: mag; the revised flux densities are 0.16 mJy, 0.22 mJy, and 0.34 mJy, line_7: respectively. These values are used in the following calculations. line_8: FOS, G130H grating, blue digicon: At 1400 A, the efficiency is 0.007. The line_9: throughput of the 1" circular aperture is 0.27 for point sources, and we have line_10: 1.0 A/diode. Using equation (5) of Table 1.2.1 in the FOS Instrument Handbook, line_11: we find a count rate of 0.015 per second per diode. Zodiacal light, airglow, line_12: diffuse Galactic light, and the dark current are all significantly less than line_13: this. For S/N = 8, we require an exposure time of about 75 minutes. line_14: Similarly, for the G190H grating + red digicon, at 1700 A the efficiency is line_15: 0.02 and the throughput is 0.30; there are 1.47 A/diode. The derived count line_16: rate is 0.078 per second per diode in the continuum. For S/N = 13, the exposure line_17: time is about 36 minutes. Finally, for the G270H grating + red digicon, at line_18: 2300 A the continuum count rate is 0.44 per second per diode, so the exposure line_19: time is 18 minutes for S/N = 22. line_20: For the FOC and the F210M + F220W filter combination, 750 sec are line_21: required for S/N = 8 per pixel. The F600M filter requires 270 sec. This line_22: will allow us to carefully examine the UV continuum morphology, and to make line_23: comparisons with the red continuum morphology. ! question: 5 section: 1 line_1: Originally I had assumed that ACQ/BINARY would be used to acquire the line_2: target. However, during a visit to STScI I was told this would be quite risky line_3: for a galaxy, even though it has a star-like nucleus (it is an active galaxy). line_4: The reason is that the background is uneven, and also the apparent brightness line_5: depends on how much of the "fuzz" is integrated. Moreover, the nucleus itself line_6: might even be resolved on the 0.3" scale. So, I reluctantly decided to play line_7: it safe and use ACQ/PEAK instead. Since the total spacecraft time does not line_8: exceed 6 hours, the peak-up can be done for only the red (or blue) side line_9: (i.e., side-switching IS allowed). I have put relatively long integration line_10: times for the dwells, in order to be certain of getting enough counts for line_11: successful acquisition. The first spatial scan will be 3 X 1 with the 4.3" line_12: aperture; each dwell should be 1 s on the red side (or 7 s on the blue side). line_13: The second spatial scan will be 2 X 6 with the 1" circular aperture; each line_14: dwell should be 2 s on the red side (or 11 s on the blue side). The third line_15: peak-up will be 3 X 3 with the 0.5" circular aperture; each dwell should be line_16: 3 s on the red side (or 18 s on the blue side). The science observations will line_17: be conducted with the 1.0" circular aperture. line_18: If it turns out that the extra time for peak-up acquisitions is NOT line_19: charged to the GO, please ADD 23M (total = 98M) to the FOS/BL G130H science line_20: integration (exposure line 6). This will make the total time equal to line_21: the allocated spacecraft time, if ACQ/BINARY had been used. Thank you. ! question: 6 section: 1 line_1: None. ! question: 7 section: 1 line_1: The calibrated one-dimensional FOS spectra will be measured and analyzed line_2: with an extensive program written by the PI. All absorption and emission lines line_3: will be measured, and the continuum spectral energy distribution will be line_4: quantified. The profiles of the emission lines will be carefully examined line_5: in order to search for broad wings (as in a Seyfert 1 nucleus). We will also line_6: try to detect the presence of broad Fe II blends in the range 1900-3000 A. line_7: If stellar absorption lines are visible, the stellar population responsible line_8: for the observed continuum will be estimated using spectral synthesis line_9: techniques. The method will follow, with a few modifications, that described line_10: by Fanelli, O'Connell, & Thuan (1988, ApJ, 334, 665). Initial input parameters line_11: for the dominant luminous constituents will be based on comparisons of our line_12: spectrum with reference spectra of stars in Wu et al. (1983, The IUE line_13: Ultraviolet Spectral Atlas) and in the library of far-UV spectra developed by line_14: Fanelli, O'Connell, & Thuan (1987, ApJ, 321, 768). line_15: The FOC images will be reduced and analyzed with standard image processing line_16: software. It should be possible to run image deconvolution algorithms in order line_17: to improve the effective spatial resolution of the data (e.g., King et al. line_18: 1991, AJ, 102, 1553; Macchetto et al. 1991, ApJL, 369, L55). Some algorithms line_19: achieve superior spatial resolution at the expense of less reliable line_20: photometry, whereas others preserve the photometric integrity of the data line_21: while giving only moderate resolution. We will use a variety of techniques to line_22: obtain the maximum amount of information from the data. The morphology of any line_23: extended component to the continuous emission will be determined. ! question: 8 section: 1 line_1: When our HST observing dates become known, we will request nearly line_2: simultaneous time at Lick Observatory to obtain optical spectra and images, line_3: IR images, and (if possible) IR spectra. These data will be combined with line_4: the UV spectra to construct an overall continuum spanning a large wavelength line_5: range. A complete analysis of the data will subsequently be done. No funds line_6: are being requested here to support the ground-based observations. ! question: 9 section: 1 line_1: A. V. Filippenko, PI: GO 2590, "Deep Imaging of the Site of SN 1961V, a line_2: Possible Extragalactic Eta Carinae Analogue." Not related to this project. line_3: A. V. Filippenko, Co-I: GO 3484, "Probing the Nuclear Regions of the line_4: Seyfert Galaxy NGC 5548." (PI: B. M. Peterson). Not related to this project. line_5: A. V. Filippenko, PI: GO 3507, "UV Spectroscopy and High-Resolution Imaging line_6: of NGC 4395, the Least Luminous and Nearest Known Seyfert 1 Nucleus." line_7: Not related to this project, but shows that the data quality for NGC 4922B line_8: should be adequate. (NGC 4395 is somewhat fainter than NGC 4922B in the UV.) line_9: A. V. Filippenko, Co-I: GO 3519, "UV Imaging of Nearby Galaxies." line_10: (PI: D. Maoz.) Not related to this project. line_11: A. V. Filippenko, Co-I: GO 3810, "The Stellar Content of Wolf-Rayet line_12: Galaxies." (PI: P. Conti.) Not related to this project. line_13: In addition, Filippenko was involved in one of the discoveries made by line_14: the QSO Snapshot Survey (PI: J. N. Bahcall.) ! question: 9 section: 2 line_1: GO 2590: Data were received a few months ago, and are currently being line_2: analyzed. An object has been detected at the position of SN 1961V; color line_3: information is being used to determine whether this is the supernova line_4: remnant, the surviving "progenitor," or an unrelated object. line_5: GO 3507: We recently received the data. Preliminary analysis reveals line_6: strong emission lines similar to those of luminous Seyfert 1 nuclei (e.g., line_7: C IV 1549, C III] 1909, Mg II 2800) superposed on a weak continuum. The line_8: nucleus seems unresolved on a scale of 1 pc (0.1"). Thus, NGC 4395 appears line_9: to contain a bona fide Seyfert 1 nucleus, but with an absolute blue magnitude line_10: of only -10 --- comparable to very luminous stars line_11: Other proposals: Data not obtained yet. ! question: 9 section: 3 line_1: "A Gravitational Lens Candidate Discovered with the Hubble Space line_2: Telescope." D. Maoz, J. N. Bahcall, D. P. Schneider, R. Doxsey, N. A. line_3: Bahcall, A. V. Filippenko, W. M. Goss, O. Lahav, and B. Yanny; line_4: Astrophysical Journal (Letters), 386, L1, 1992. ! question: 10 section: 1 line_1: The U. C. Berkeley Astronomy Department has extensive computing facilities line_2: (VMS and UNIX). Image-processing workstations, graphics terminals, laser line_3: printers, large disks, and tape drives are all available. Numerous computer line_4: programs exist for analysis of data. Co-I Luis Ho, an outstanding graduate line_5: student whose doctoral thesis is on AGNs, will do a substantial fraction of line_6: the analysis. Additional ground-based complementary observations may readily line_7: be obtained at Lick Observatory; we hope to also use the Keck telescope this line_8: year. The usual secretarial and technical support is available at U.C. Berkeley. ! !end of general form text general_form_address: lname: FILIPPENKO fname: ALEXEI mi: V. title: PROF. category: PI inst: UC-Berkeley addr_1: DEPARTMENT OF ASTRONOMY addr_2: 601 CAMPBELL HALL addr_3: UNIVERSITY OF CALIFORNIA city: BERKELEY state: CA zip: 94720 country: USA phone: 510-642-1813 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC4922B descr_1: E,312,320,910 pos_1: RA = 12H 59M 01.32S +/- 0.06S, pos_2: DEC = +29D 34' 55.7" +/- 0.6" equinox: 1950.0 rv_or_z: Z = 0.024 comment_1: MAGNITUDES AND FLUXES comment_2: REFER TO NUCLEUS ONLY. comment_3: BRIGHT NUCLEUS SUPERPOSED ON comment_4: FAINTER GALAXY BACKGROUND. comment_5: PI HAS COMPARED THESE COORDS TO comment_6: GASP, AND PREFERS THESE. - 2/11/93 fluxnum_1: 1 fluxval_1: V = 16.0 +/- 0.4 fluxnum_2: 2 fluxval_2: B-V = 0.5 +/- 0.3 fluxnum_3: 3 fluxval_3: F-CONT(1400) = 2.4 +/- 0.7 E-15 fluxnum_4: 4 fluxval_4: F-CONT(1700) = 2.3 +/- 0.7 E-15 fluxnum_5: 5 fluxval_5: F-CONT(2300) = 1.9 +/- 0.6 E-15 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC4922B config: FOS/RD opmode: ACQ/PEAK aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 1S fluxnum_1: 1 fluxnum_2: 2 priority: 1 req_1: ONBOARD ACQ FOR 2; req_2: SPATIAL SCAN; req_3: CYCLE 3 / 1-8; req_4: GROUP 1-6 NO GAP; comment_1: BLUE SIDE ACQ/PEAK: comment_2: SP-ELEMENT=MIRROR, EXP = 7S comment_3: IF BLUE SIDE NEEDED. ! linenum: 2.000 targname: NGC4922B config: FOS/RD opmode: ACQ/PEAK aperture: 1.0 sp_element: MIRROR num_exp: 1 time_per_exp: 2S fluxnum_1: 1 fluxnum_2: 2 priority: 1 req_1: ONBOARD ACQ FOR 3; req_2: SPATIAL SCAN; comment_1: BLUE SIDE ACQ/PEAK: comment_2: SP-ELEMENT=MIRROR, EXP = 11S comment_3: IF BLUE SIDE NEEDED. ! linenum: 3.000 targname: NGC4922B config: FOS/RD opmode: ACQ/PEAK aperture: 0.5 sp_element: MIRROR num_exp: 1 time_per_exp: 3S fluxnum_1: 1 fluxnum_2: 2 priority: 1 param_1: SCAN-STEP=0.35, param_2: SEARCH-SIZE=3 req_1: ONBOARD ACQ FOR 4-6; comment_1: BLUE SIDE ACQ/PEAK: comment_2: SP-ELEMENT=MIRROR, EXP = 18S comment_3: IF BLUE SIDE NEEDED. ! linenum: 4.000 targname: NGC4922B config: FOS/RD opmode: ACCUM aperture: 1.0 sp_element: G270H wavelength: 2760 num_exp: 1 time_per_exp: 18M s_to_n: 22 fluxnum_1: 5 priority: 1 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULTATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 5.000 targname: NGC4922B config: FOS/RD opmode: ACCUM aperture: 1.0 sp_element: G190H wavelength: 1950 num_exp: 1 time_per_exp: 36M s_to_n: 13 fluxnum_1: 4 priority: 2 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULTATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 6.000 targname: NGC4922B config: FOS/BL opmode: ACCUM aperture: 1.0 sp_element: G130H wavelength: 1380 num_exp: 1 time_per_exp: 75M s_to_n: 8 fluxnum_1: 3 priority: 3 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULTATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 7.000 targname: NGC4922B config: FOC/96 opmode: IMAGE aperture: 512X512 sp_element: F210M,F220W wavelength: 2150 num_exp: 1 time_per_exp: 750S s_to_n: 8 fluxnum_1: 4 fluxnum_2: 5 priority: 4 req_1: GROUP 7-8 NO GAP; comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULTATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 8.000 targname: NGC4922B config: FOC/96 opmode: IMAGE aperture: 512X512 sp_element: F600M wavelength: 5800 num_exp: 1 time_per_exp: 270S s_to_n: 8 fluxnum_1: 1 fluxnum_2: 2 priority: 5 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULTATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! ! end of exposure logsheet scan_data: line_list: 1 fgs_scan: cont_dwell: D dwell_pnts: 3 dwell_secs: 1.00 scan_width: 0.0000 scan_length: 2.8000 sides_angle: 90.0000 number_lines: 1 scan_rate: 0.0000 first_line_pa: 0.0000 scan_frame: S/C len_offset: 1.4000 wid_offset: 0.0000 ! line_list: 2 fgs_scan: cont_dwell: D dwell_pnts: 6 dwell_secs: 1.00 scan_width: 0.7000 scan_length: 3.5000 sides_angle: 90.0000 number_lines: 2 scan_rate: 0.0000 first_line_pa: 90.0000 scan_frame: S/C len_offset: 1.7500 wid_offset: 0.3500 ! ! end of scan data