! File: 4512C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:15:36:41 coverpage: title_1: NGC 628: COULD IT BE A PROTOTYPE "QSO ABSORPTION-LINE SYSTEM" - title_2: CYCLE 3 SUPPLEMENTAL sci_cat: QUASARS & AGN sci_subcat: QUASAR ABSORPTION proposal_for: GO pi_fname: FRANK pi_mi: H pi_lname: BRIGGS pi_inst: 3170 pi_country: U.S.A. hours_pri: 4.58 num_pri: 1 fos: Y funds_length: 12 off_fname: MICHAEL off_mi: M off_lname: CROUCH off_title: DIRECTOR off_inst: 3170 off_addr_1: OFFICE OF RESEARCH off_addr_2: 350 THACKERAY off_addr_3: UNIVERSITY OF PITTSBURGH off_city: PITTSBURGH off_state: PA off_zip: 15260 off_country: U.S.A. off_phone: 412-624-7400 ! end of coverpage abstract: line_1: The ScI galaxy NGC 628 is embedded in a giant, warped disk of neutral line_2: gas whose size nearly matches the cross-section inferred for the line_3: intervening absorbers identified in the spectra of high redshift QSOs. line_4: The galaxy may resemble the narrow, low-ionization systems identified line_5: by the MgII doublet 2796,2802 and the other common ISM lines of FeII, line_6: SiII, CII, OI, etc. Fortuitously, a background QSO lies line_7: behind the the most extended part of the gas distribution, and the QSO line_8: continuum can be used to probe the gas for the presence of metals by line_9: searching for the MgII doublet in absorption at the known redshift of line_10: this fore-ground galaxy. The observation will place strict constraints line_11: on the history of stellar populations and metal enrichment of these line_12: galactic outskirts that are not detectable in optical emission but line_13: comprise one tenth of the galaxy's neutral gas content. ! ! end of abstract general_form_proposers: lname: BRIGGS fname: FRANK title: PI mi: H inst: UNIVERSITY OF PITTSBURGH country: U.S.A. ! lname: TURNSHEK fname: DAVID mi: A inst: UNIVERSITY OF PITTSBURGH country: U.S.A. ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: ! question: 3 section: 1 line_1: This request is for a single FOS G270H spectrum of a QSO at resolution R=1000 line_2: yielding a signal-to-noise ratio of 30 per resolution element. The 1 arcsec FOS line_3: aperture will be used. The exposure time will be 275M. ! question: 4 section: 1 line_1: The only way to observe the spectrum of this background QSO at the expected line_2: position of the MgII2800 absorption doublet is to obtain observations in the line_3: UV. This region of the UV is not accessible from the ground. This QSO is not line_4: bright enough for this observation to be performed with IUE. line_6: Using the FOS G270H mode and 1 arcsec aperture, an exposure time of 275M is line_7: required to obtain a spectrum with a signal-to-noise ratio of 30 per resolution line_8: element at the expected position of the MgII2800 doublet. With the aperture we line_9: propose to use the resolution will be R=1000 which is 5 pixels in 1/4-diode line_10: substepping mode (or 2.8 Angstroms resolution). The 1-sigma error in an line_11: absorption line equivalent width measurement will be approximately 0.1 line_12: Angstrom. (This sensitivity is high enough to insure that MgII with line_13: "depleted abundances" typical of neutral clouds in the Milky Way would be line_14: detected at the 5-sigma level; a non-detection would imply that the abundance line_15: of MgII is less than 1/300 solar-abundance with 95% confidence.) line_16: This exposure time was determined using the FOS simulator software on line_17: SCIVAX at STScI. ! question: 5 section: 1 line_1: ! question: 6 section: 1 line_1: ! question: 7 section: 1 line_1: The data will be reduced and processed on SUN workstations using the software line_2: available in IRAF/STSDAS when possible. The spectra will be examined for line_3: the presence of MgII (and MgI) absorption. A continuum level will be fit line_4: to the spectrum and the equivalent widths of the MgII lines measured. The lines line_5: will be interpreted in the context of the curve of growth in Figure 2. If the line_6: lines are substantially stronger than predicted, then there must be an line_7: additional high-velocity-dispersion component of halo clouds present and line_8: a range of more complex models will be considered. If no detection is made, line_9: limits will be placed on the metal abundances in the gas. The constraints on line_10: the history of this outlying material will help in deciphering the dynamics line_11: at work in this galaxy: The absence of metals could indicate a very real line_12: possibility of accretion of primordial material from outside the galaxy or line_13: perhaps that stars have never formed in this outlying gas. line_14: The detection of metals implies that star formation and evolution line_15: have already occured, either in an early burst of star formation in the outer line_16: part of NGC628 or in a gas-rich dwarf galaxy that has been captured and line_17: tidally dispersed as it is assimilated into the disk of NGC 628. Clearly, line_18: even a crude knowlege of the metal abundances in this material would restrict line_19: the range of possible scenarios. ! question: 8 section: 1 line_1: ! question: 9 section: 1 line_1: For PI Briggs: No HST time or archival data has been received. line_3: For co-I Turnshek: line_5: The GTO program 1146 entitled "Spectroscopic Studies of Several High Redshift line_6: BAL QSOs" has been reduced in scope due to the problems with HST. However, line_7: FOS G270H observations of one BAL QSO have been made (Korista et al. 1992) and line_8: an FOS G190H observation is scheduled. The program is a line_9: collaboration between Weymann (PI), Burbidge, Cohen, Foltz, Hartig, line_10: Junkkarinen, Morris, and Turnshek. This program is not directly related to the line_11: project proposed here. line_13: The GTO program 1145 entitled "Imaging and Spectroscopy of the Low Redshift line_14: BAL QSO PG 1700+518" has been deferred until the imaging capabilities of HST are line_15: fully restored (estimated Cycle 5). This program is not related to the project line_16: proposed here. line_18: The GO key project program 2424 (and continuation 3353) entitled "Quasar line_19: Absorption Line Survey" is a collaboration between Bahcall (PI), Bergeron, line_20: Boksenberg, Hartig, Jannuzi, Sargent, Savage, Schneider, Turnshek, Weymann, line_21: and Wolfe. This Cycle 1, 2, and 3 program is designed to line_22: redshifted QSO absorption line systems that are selected in the line_23: observations of bright QSOs. It is program that is complementary ! question: 9 section: 2 line_1: to the current proposal but fundamentally different in goals and line_2: approach. line_4: The GO program 2649 entitled "Spectrophotometry of the Lensed Clover Leaf BAL line_5: QSO 1413+11" is a collaboration between Turnshek (PI) and Lupie. This Cycle 1 line_6: program is not related to the project proposed here. line_8: The GO program 3660 entitled "The Level of Ionization and Chemical Composition line_9: of QSO BAL Region Gas" is a collaboration between Turnshek (PI), Espey, and line_10: Weymann. This Cycle 2 program is not related to the project proposed here. line_12: "HST-FOS and Ground-Based Observations of the BAL Quasar 0226-1024" by line_13: Korista, Weymann, Morris, Kopko, Turnshek, Hartig, Foltz, Burbidge, and line_14: Junkkarinen, ApJ, in press, 1992. line_16: "The HST Quasar Absorption Line Key Project I. First Observational Results line_17: Including Lyman-ALPHA and Lyman-Limit Systems" by Bahcall, Bergeron, line_18: Boksenberg, Hartig, Jannuzi, Kirhakos, Sargent, Savage, Schneider, Turnshek, line_19: Weymann, and Wolfe, ApJ, in press, 1992. line_21: "The HST Quasar Absorption Line Key Project II. Data Calibration and line_22: Absorption Line Selection" by Schneider, Hartig, Jannuzi, Kirhakos, Saxe, line_23: Weymann, Bahcall, Bergeron, Boksenberg, Sargent, Savage, Turnshek, and ! question: 9 section: 3 line_1: Wolfe, ApJ, submitted, 1992. ! question: 10 section: 1 line_1: Institutional support includes academic salary for the PI and co-I. The line_2: University of Pittsburgh will also supply routine secretarial assistance, line_3: administrative support, and the office space required for this project. In line_4: addition, the University has a pool of graduate and undergraduate research line_5: assistants who can be called upon to perform work for this project, providing line_6: that the work can be charged to project funds. The Department of line_7: Physics and Astronomy operates a SUN SPARC2 which line_8: acts as a file server for client workstations owned by various research line_9: groups. Other departmental facilities include a laser printer, a CD reader, and line_10: an exabyte 8mm tape drive. The department pays for a maintenance contract on line_11: its computer hardware. However, the departmental computing facilities are not line_12: generally used by the various physics and astronomy research groups (except for line_13: the file server capability). Their primary purpose is as an educational tool. line_14: However, they would prove to be a good backup in the event that, for example, line_15: the computing facilities of the astronomy/astrophysics group go down. Research line_16: groups must purchase and maintain their computing facilities with project line_17: funds. ! !end of general form text general_form_address: lname: Briggs fname: Frank mi: H category: PI inst: UNIVERSITY OF PITTSBURGH addr_1: Department of Physics and Astronomy addr_2: Allen Hall addr_3: ALLEGHANY OBSERVATORY city: Pittsburgh state: PA zip: 15260 country: U.S.A. phone: 412-624-9026/9000 telex: None ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC628Q1 descr_1: E,313 pos_1: RA = 01H 36M 03.9S +/- 0.1S, pos_2: DEC = +15D 37' 58" +/- 1.0" equinox: 2000 rv_or_z: Z = 2.149 fluxnum_1: 1 fluxval_1: V = 19.0 fluxnum_2: 2 fluxval_2: F-CONT(2700) = 1.3 E-16 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC628Q1 config: FOS/RD opmode: ACQ/PEAK aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 12.0S s_to_n: 30 fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE-X=1 param_2: SEARCH-SIZE-Y=3 param_3: SCAN-STEP-Y=1.4 req_1: CYCLE 3 / 1-2; req_2: ONBOARD ACQ FOR 1.1 ! linenum: 1.100 targname: NGC628Q1 config: FOS/RD opmode: ACQ/PEAK aperture: 1.0 sp_element: MIRROR num_exp: 1 time_per_exp: 20.0S s_to_n: 30 fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE-X=6 param_2: SCAN-STEP-X=0.7 param_3: SEARCH-SIZE-Y=2 param_4: SCAN-STEP-Y=0.7 req_1: ONBOARD ACQ FOR 1.2 ! linenum: 1.200 targname: NGC628Q1 config: FOS/RD opmode: ACQ/PEAK aperture: 0.5 sp_element: MIRROR num_exp: 1 time_per_exp: 40.0S s_to_n: 30 fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE-X=3 param_2: SCAN-STEP-X=0.35 param_3: SEARCH-SIZE-Y=3 param_4: SCAN-STEP-Y=0.35 req_1: ONBOARD ACQ FOR 2 ! linenum: 2.000 targname: NGC628Q1 config: FOS/RD opmode: ACCUM aperture: 1.0 sp_element: G270H num_exp: 1 time_per_exp: 271M s_to_n: 30 fluxnum_1: 2 priority: 1 ! ! end of exposure logsheet ! No scan data records found