! Proposal 6464, submission 1 ! PI: Dante Minniti ! Received Wed Feb 7 12:45:45 EST 1996 ! From: dminniti@igpp.llnl.gov ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6464,v 3.1 1996/02/12 15:00:17 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6464,v 3.1 1996/02/12 15:00:17 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Sleiman ! Phone: 410-338-4753 , E-mail: sleiman@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0213.minniti.prop ! Date generated: Fri Dec 22 18:11:51 EST 1995 ! Proposal_Information ! Section 4 Title: RESOLVING STARS AROUND THE NEAREST KNOWN SEYFERT 1 NUCLEUS Proposal_Category: GO Scientific_Category: AGN Cycle: 6 Investigators PI_name: Dante Minniti PI_Institution: Lawrence Livermore National Laboratory CoI_Name: Pascale Jablonka CoI_Institution: Observatoire de Paris Meudon Contact: ! Y or N (designate at most one contact) CoI_Name: Alex Filippenko CoI_Institution: University of California, Berkeley Contact: ! Y or N (designate at most one contact) CoI_Name: Robert Fosbury CoI_Institution: Hubble Space Telescope, European Coordinating Facility Contact: ! Y or N (designate at most one contact) CoI_Name: Joseph Shields CoI_Institution: Steward Observatory Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) NGC 4395 is the least luminous and nearest known Seyfert 1 galaxy, serendipitously discovered by Filippenko & Sargent (1989). We propose to obtain deep BVI images of the nuclear region of this galaxy with the WFPC2, in order to make color- magnitude and color-color diagrams of the surrounding stars. These will allow us to determine: 1) the distance to NGC 4395, 2) the ages of the young populations around the Seyfert nucleus, 3) the ages of the old populations, and 4) their metal abundances. Our overall goal is to study how an AGN influences the circumnuclear stellar population, as well as stellar influences on nuclear activity. NGC 4395 is an important target for study since it is nearby, is almost face on, does not have a bulge, and apparently is subject to little extinction by dust in its central region. This proposal focuses on the stellar content around the active nucleus, an aspect yet unstudied, that will be complemented with the following ground and space based observations: 1) HST pre- repair optical imaging and UV spectroscopy 2) ISO emission- line spectroscopy, 3) Lick imaging and spectroscopy, and 4) Keck high resolution spectroscopy. Using the superb resolution of WFPC2 we would be able to directly test the effects of an active nucleus on the star formation history of an otherwise normal galaxy. Questions ! Free format text (please update) Observing_Description: The proposed images need to be deep enough in V and I to resolve the RGB tip (I_0 = -4.0) for the old stellar component, and photometry in B must be go sufficiently faint to measure the brightness of the blue main sequence with ages younger than ~ 10^8 yr (B_0 ~ -5). The corresponding limiting apparent magnitudes depend on the distance adopted, and for purposes of this proposal we conservatively adopt the large distance of Sandage (1988), D = 6.5 Mpc. The limiting magnitudes (S/N = 10) that we want to reach are thus B=24.1, V=26.6, and I = 25.1, corresponding to total exposure times of 10500, 2700, and 2400 sec for these bandpasses, respectively. These exposure times, computed using the new WFPC2 time calculator, add up to a total of 6 orbits., We have observed distant galaxies (D=1.5--2 Mpc) with the ESO NTT under superb seeing conditions, resolving at the limit the stars in the RGB tip (Minniti & Zijlstra 1995). However, our experience with these data indicate that similar observations of the nuclear region of NGC 4395 would not resolve the individual stars due to crowding. We have computed the expected number of tip red giant branch stars per unit area corresponding to the observed surface brightness in this region, following the procedure outlined by Renzini (1992). The resulting ~1 star/arcsec^2 determines that only HST can achieve the required resolution., In order to obtain the best possible sampling and photometry, we will use the dithering techniques developed at ST-ECF and STScI (e.g. Dickinson & Fosbury 1995, Adorf 1995). We will use DAOPHOT II, and APPHOT to do the photometric measurements, deciding from their comparative performances which one is best in this case., References, Adorf, H.-M. 1995, ST-ECF Newsletter No. 23, p. 19 Dickinson, M., & Fosbury, R. 1995, ST-ECF Newsletter No. 22, p. 14 Minniti, D., & Zijlstra, A. 1995, ApJ, to be submitted Renzini, A. 1992, in IAU Symp. 153 ``Galactic Bulges", eds. H. Dejonghe & H. Habing (Dordrecht: Kluwer), p. 151 Sandage, A. 1988, ApJ, 331, 605 Real_Time_Justification: None. This proposal focuses on the stellar content around the active nucleus, an aspect yet unstudied, that will be complemented with the following ground and space based observations: 1) HST pre-repair imaging and spectroscopy, 2) ISO observations, 3) Lick imaging and spectroscopy, and 4) Keck spectroscopy. We will probably request deep K band photometry with HST + NICMOS in the next cycles. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: NGC4395 Alternate_Names: Description: Galaxy,Seyfert Position: RA=12H 25M 48.80S +/- 0.1S, DEC=33D 32' 47.8" +/- 1", ! PLATE-ID=0000 Equinox: J2000 RV_or_Z: V=+317 RA_PM: 0.0 ! Units are seconds of time per year Dec_PM: 0.0 ! Units are seconds of arc per year Epoch: Annual_Parallax: 0.0 Flux: V=17.0 +/- 0.5, B-V=0.36 +/- 0.2 ! Include at least V and B-V Comments: Magnitude and color of the Seyfert nucleus listed. ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: 1 Visit_Requirements: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! DROP TO GYRO IF NECESSARY [NO REACQuisition] ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! SCHEDulability ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN