! File: 3507C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:10:14:57 coverpage: title_1: ULTRAVIOLET SPECTROSCOPY AND HIGH-RESOLUTION IMAGING OF NGC 4395, THE title_2: LEAST LUMINOUS AND NEAREST KNOWN SEYFERT 1 NUCLEUS sci_cat: QUASARS & AGN sci_subcat: SEYFERTS proposal_for: GO pi_fname: ALEXEI pi_mi: V pi_lname: FILIPPENKO pi_inst: UNIVERSITY OF CALIFORNIA AT BERKELEY pi_country: USA pi_phone: 510-642-1813 hours_pri: 7.01 num_pri: 1 wf_pc: Y fos: Y funds_length: 12 off_fname: MARION off_mi: B off_lname: LENTZ off_title: RES. ADMINISTRATOR off_inst: UNIVERSITY OF CALIFORNIA AT BERKELEY off_addr_1: SPONSORED PROJECTS OFFICE off_addr_2: 300 SPROUL HALL off_city: BERKELEY off_state: CA off_zip: 94720 off_country: USA off_phone: 510-642-8120 ! end of coverpage abstract: line_1: We have discovered the least luminous known Seyfert 1 nucleus, in the very line_2: nearby (d = 2.6 Mpc), Sd III-IV galaxy NGC 4395. Seyfert 1 nuclei have never line_3: before been seen in galaxies of such late Hubble type, and so nearby. The line_4: luminosity of the broad H-alpha emission line is a factor of 10 lower than in line_5: M81, the previous champion. The blue continuum magnitude of the nucleus is -10, line_6: no brighter than a cluster of luminous stars; thus, it is remotely possible line_7: that the object itself can be explained by purely stellar phenomena, rather line_8: than by accretion onto a black hole. In order to test this hypothesis, and to line_9: further explore the unique properties of the active nucleus in NGC 4395, we line_10: propose to obtain UV spectra as part of an ongoing multi-wavelength study of line_11: this object. Detailed comparisons will be made with the spectra of typical line_12: luminous Seyfert 1 nuclei. A search will be made for absorption features line_13: produced by hot stars. We will determine whether the continuum has a "big blue line_14: bump" (like other type 1 Seyferts), and we will examine various emission-line line_15: intensity ratios to see whether a nonstellar photoionizing continuum is line_16: required. Since the active nucleus is in a spatially well-resolved galaxy, the line_17: spectra will not be contaminated by starlight from a galactic bulge. A direct line_18: image of NGC 4395, obtained with the PC, will show whether the active nucleus line_19: is a true point source less than 1 pc in size, rather than an extended source line_20: (such as a collection of very hot stars). ! ! end of abstract general_form_proposers: lname: FILIPPENKO fname: ALEXEI title: PI mi: V inst: UNIVERSITY OF CALIFORNIA AT BERKELEY country: USA ! lname: SARGENT fname: WALLACE mi: W inst: CALIFORNIA INSTITUTE OF TECHNOLOGY country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: SPECTROSCOPY. To detect faint features, and to study the profiles of line_2: emission lines and absorption lines, we require spectra having good S/N line_3: ratio and moderately high resolution over most of the UV wavelength range. line_4: We will connect the red end of the UV spectrum with our optical/IR spectrum, line_5: obtained at ground-based observatories. The resulting spectrum covering a line_6: broad range will allow us to measure accurate emission-line intensity ratios line_7: and continuum colors. Three HST grating settings are needed, as follows: line_8: (1) FOS, G130H grating, 1150-1608 A, 1.0 A/diode, blue digicon. line_9: (2) FOS, G190H grating, 1573-2323 A, 1.5 A/diode, red digicon. line_10: (3) FOS, G270H grating, 2227-3306 A, 2.1 A/diode, red digicon. line_11: The FOS spectra will be obtained through the 4.3" X 4.3" aperture. This line_12: yields the best throughput, and the resulting resolution will be adequate line_13: for our purposes. We can use such a large aperture without worrying about line_14: contamination from circumnuclear stars because the bulge of NGC 4395 is line_15: almost nonexistent. line_16: IMAGING. To see if the nucleus of NGC 4395 is spatially extended, we line_17: will obtain images with the PC. We will take one exposure in each of line_18: the F336W, F547M, and F785LP filters. Emission lines are weak or absent in line_19: all cases, and the different exposures can be used to eliminate cosmic rays. line_20: We agree with the assessment of the TAC that a narrow-band [O III] image line_21: would also be useful, and we now plan to obtain one. To eliminate cosmic line_22: rays and test for image stability, a second narrow-band image will be line_23: obtained, but at H-beta. ! question: 4 section: 1 line_1: The nucleus of NGC 4395 is very faint at UV wavelengths. If a power law of line_2: index -1.5 is used to extrapolate the observed optical flux to the UV range, line_3: we find that the nuclear continuum flux density at 2000 A is about 0.1 mJy. line_4: This may be compared with 0.2 mJy for the faintest Seyfert nuclei successfully line_5: observed by IUE. (The resulting IUE spectra had low S/N ratios.) Nevertheless, line_6: in 1989 we applied for, and received, some time with IUE, in order to get a line_7: rough indication of the UV properties of NGC 4395. Unfortunately, it turned line_8: out that there were no suitable guide stars in the restricted field available line_9: to the IUE FES. However, the IUE data probably would not have given us line_10: much information; the review panel concluded that "[our proposed study] looks line_11: like one of those excellent projects which should be reserved for ST." line_12: The necessity of HST is also obvious for imaging NGC 4395. We are trying to line_13: see whether the nucleus is spatially resolved. The best ground-based image line_14: we have been able to obtain has stellar seeing disks of 1.0", or about 13 pc line_15: at the distance of NGC 4395. Even with 0.5" seeing, rarely available from line_16: ground-based observatories, the upper limit to the volume of an unresolved line_17: nucleus is at least 100 times larger than is currently achievable with HST. line_18: Constraints on the nature of the activity in the nucleus of NGC 4395 become line_19: progressively more severe as we increase the spatial resolution. ! question: 7 section: 1 line_1: The data will be reduced with standard programs (IRAF, etc.). Special care line_2: will be taken to use the best image reconstruction techniques when analyzing line_3: the PC images; we want to achieve the highest possible resolution. line_4: When our HST observing dates become known, we will request nearly simultaneous line_5: time at Lick and Palomar Observatories to obtain optical spectra and images, line_6: IR images, and IR spectra. These data will be combined with the UV spectra to line_7: construct an overall continuum spanning a large wavelength range. We will line_8: also schedule VLA observations on, or near, the appropriate dates. A complete line_9: analysis of the data will subsequently be done. line_10: Measurement and analysis of the calibrated one-dimensional spectra will be line_11: done with an extensive program written by the PI for his studies of optical line_12: spectra. All emission lines will be measured (wavelengths, fluxes, equivalent line_13: widths, velocity widths), and the continuum shape will be determined. A search line_14: will be made for absorption lines, which might reveal the presence of very hot line_15: stars. The continuum flux will be extrapolated beyond the Lyman limit, to see line_16: whether it can indeed account for the emission lines. A photoionization code line_17: (CLOUDY) will then be used to analyze the overall emission-line spectrum using line_18: the observed continuum, together with the derived density and temperature, as line_19: input parameters. The possibility of stellar versus nonstellar photoionization line_20: will be examined. Comparisons with shock models will also be made. ! question: 9 section: 1 line_1: Alexei 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: Wallace W. Sargent, Co-I: GO 2078, "A Search for Primordial Gas: is I Zw 18 line_4: a Young Galaxy?" (PI: James Lequeux). Not related to this project. line_5: Wallace W. Sargent, Co-I: GO 2424, "Quasar Absorption Line Survey" (PI: line_6: John N. Bahcall). Not related to this project. line_7: Some HST data have been obtained for the above programs; analysis is in line_8: progress. ! question: 10 section: 1 line_1: Both Caltech and U. C. Berkeley have extensive computing facilities (VMS line_2: and UNIX) in their Astronomy Departments. Image-processing workstations, line_3: graphics terminals, laser printers, large disks, and tape drives are all line_4: available. Many computer programs exist for analysis of data. Both line_5: institutions also have many extremely capable graduate students, one of line_6: whom will participate in various aspects of this project. Ground-based line_7: complementary observations may readily be obtained at both Palomar and line_8: Lick Observatories. The usual secretarial and technical support is available line_9: at Caltech and Berkeley. ! !end of general form text general_form_address: lname: FILIPPENKO fname: ALEXEI mi: V category: PI inst: UNIVERSITY OF CALIFORNIA AT 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: NGC4395 descr_1: E,301,312,910 pos_1: RA = 12H 23M 19.84S +/- 0.1S, pos_2: DEC = +33D 49' 24.3" +/- 1" equinox: 1950.0 pm_or_par: N rv_or_z: V = +317 acqpr_1: BKG comment_1: MAGNITUDES AND FLUXES comment_2: REFER TO NUCLEUS ONLY. fluxnum_1: 1 fluxval_1: V = 17.0 +/- 0.5 fluxnum_2: 2 fluxval_2: B-V = 0.36 +/- 0.2 fluxnum_3: 3 fluxval_3: F-LINE(5007) = 6 +/- 1 E-16 fluxnum_4: 4 fluxval_4: W-LINE(5007) = 310 +/- 50 fluxnum_5: 5 fluxval_5: F-LINE(4861) = 6 +/- 1 E-16 fluxnum_6: 6 fluxval_6: W-LINE(4861) = 60 +/- 10 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC4395 config: FOS/BL opmode: ACQ/BINARY aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 69S fluxnum_1: 1 priority: 2 req_1: ONBOARD ACQ FOR 2; req_2: CYCLE 2 / 1-10; req_3: GROUP 1-2 NO GAP ! linenum: 2.000 targname: NGC4395 config: FOS/BL opmode: ACCUM aperture: 4.3 sp_element: G130H wavelength: 1380 num_exp: 1 time_per_exp: 260M s_to_n: 14 fluxnum_1: 1 fluxnum_2: 2 priority: 2 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULATATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 3.000 targname: NGC4395 config: FOS/RD opmode: ACQ/BINARY aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 26S fluxnum_1: 1 priority: 1 req_1: ONBOARD ACQ FOR 4-5; req_2: GROUP 3-5 NO GAP ! linenum: 4.000 targname: NGC4395 config: FOS/RD opmode: ACCUM aperture: 4.3 sp_element: G190H wavelength: 1950 num_exp: 1 time_per_exp: 97M s_to_n: 16 fluxnum_1: 1 fluxnum_2: 2 priority: 1 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULATATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 5.000 targname: NGC4395 config: FOS/RD opmode: ACCUM aperture: 4.3 sp_element: G270H wavelength: 2760 num_exp: 1 time_per_exp: 32.2M s_to_n: 20 fluxnum_1: 1 fluxnum_2: 2 priority: 1 comment_1: IF THERE IS EXTRA TIME BEFORE comment_2: EARTH OCCULATATION NEAR END OF comment_3: EXPOSURE, CAN INCREASE EXPOSURE comment_4: TIME TO INCREASE S/N RATIO. ! linenum: 6.000 targname: NGC4395 config: PC opmode: IMAGE aperture: PC6 sp_element: F547M wavelength: 5470 num_exp: 1 time_per_exp: 2M s_to_n: 100 fluxnum_1: 1 priority: 3 param_1: CR-SPLIT=NO param_2: PRE-FLASH=YES req_1: GROUP 6-10 NO GAP comment_1: WANT DATA FROM ALL 4 CCDS ! linenum: 7.000 targname: NGC4395 config: PC opmode: IMAGE aperture: PC6 sp_element: F336W wavelength: 3350 num_exp: 1 time_per_exp: 400S s_to_n: 50 fluxnum_1: 1 fluxnum_2: 2 priority: 3 param_1: CR-SPLIT=NO param_2: PRE-FLASH=YES comment_1: WANT DATA FROM ALL 4 CCDS ! linenum: 8.000 targname: NGC4395 config: PC opmode: IMAGE aperture: PC6 sp_element: F785LP wavelength: 8960 num_exp: 1 time_per_exp: 1M s_to_n: 60 fluxnum_1: 1 fluxnum_2: 2 priority: 3 param_1: CR-SPLIT=NO param_2: PRE-FLASH=YES comment_1: WANT DATA FROM ALL 4 CCDS ! linenum: 9.000 targname: NGC4395 config: PC opmode: IMAGE aperture: PC6 sp_element: F502N wavelength: 5016 num_exp: 1 time_per_exp: 5M s_to_n: 50 fluxnum_1: 3 fluxnum_2: 4 priority: 3 param_1: CR-SPLIT=NO param_2: PRE-FLASH=YES comment_1: WANT DATA FROM ALL 4 CCDS ! linenum: 10.000 targname: NGC4395 config: PC opmode: IMAGE aperture: PC6 sp_element: F487N wavelength: 4867 num_exp: 1 time_per_exp: 15M s_to_n: 50 fluxnum_1: 5 fluxnum_2: 6 priority: 3 param_1: CR-SPLIT=NO param_2: PRE-FLASH=YES comment_1: WANT DATA FROM ALL 4 CCDS ! ! end of exposure logsheet ! No scan data records found