! File: 4217C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:17:53:10 coverpage: title_1: THE ABSORPTION CROSS-SECTIONS OF NEARBY GALAXIES--- title_2: REPEAT FOR HOPR#56 sci_cat: QUASARS & AGN sci_subcat: QUASAR ABSORPTION proposal_for: RPT/GO cont_id: 2553 pi_fname: CHRIS pi_lname: BLADES pi_inst: SPACE TELESCOPE SCIENCE INSTITUTE hours_pri: 4.20 num_pri: 1 hrs: Y off_fname: HERVEY off_lname: STOCKMAN, JR. off_title: DEPUTY DIRECTOR off_inst: SPACE TELESCOPE SCIENCE INSTITUTE off_addr_1: 3700 SAN MARTIN DRIVE off_city: BALTIMORE off_state: MD off_zip: 21218 off_country: USA off_phone: 301-338-4730 ! end of coverpage abstract: line_1: We wish to examine the hypothesis that low-redshift galaxies are surrounded by line_2: extended gaseous haloes and disks. Specifically, we propose using the line_3: GHRS to search for Mg II and C IV absorption lines in the haloes of line_4: low-redshift galaxies lying fortuitously in front of background quasars. We line_5: aim to reach sensitive equivalent widths limits of 60 mA and 40 mA line_6: (2 sigma) for each of the ions, and hence to infer the chemical, ionization line_7: and kinematic conditions within the absorbing gas by accurately measuring line_8: column densities, doppler parameters, and the large-scale multicomponent line_9: structure of the lines. Comparisons of the absorption in nearby galaxies with line_10: the lines seen at higher redshifts in QSO spectra should help settle the issue line_11: of how the metal-line systems originate. The recent discovery of Ly alpha line_12: absorption at very low redshift in 3C 273 with the GHRS makes our line_13: proposal timely and relevant. ! ! end of abstract general_form_proposers: lname: BLADES fname: CHRIS title: PI inst: SPACE TELESCOPE SCIENCE INSTITUTE country: U.S.A. ! lname: BOWEN fname: DAVID mi: V. inst: SPACE TELESCOPE SCIENCE INSTITUTE country: U.S.A. esa: Y ! lname: PETTINI fname: MAX inst: ROYAL GREENWICH OBSERVATORY country: U.K. esa: Y ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: ! question: 3 section: 1 line_1: ! question: 4 section: 1 line_1: The study of absorption by low-redshift galactic haloes in the same ions line_2: observed at higher redshifts is arguably the most important step in line_3: understanding the nature of the absorbing galaxies in the early universe. line_5: Mg~II lines can only be observed for z > 0.2 and C~IV above z > 1.2 in the line_6: optical. These are therefore only accessible at lower redshifts with the line_7: (IUE). IUE has a small aperture which permits detection of only strong line_8: ($1-2$~\AA ) lines in the brightest quasar spectra and is unsuitable for line_9: detecting lines at the equivalent width limits (0.25~\AA ) of the higher line_10: redshift absorption line surveys. The GHRS plus HST is ideal for this study. line_11: The sensitivity of the instrument is high enough to detect weak Mg~II line_12: lines in bright quasars, and, with the intermediate-dispersion gratings, data line_13: can be obtained with a resolution which discerns the large-scale velocity line_14: structure of the absorption-line profiles. This in turn permits a more accurate line_15: determination of column densities and doppler parameters, and leads to a more line_16: detailed analysis of the chemical, ionization and kinematics of the absorbing line_17: gas. For these two reasons, the GHRS is more suitable for studying the physics line_18: of galactic haloes than the FOS. ! question: 5 section: 1 line_1: ! question: 6 section: 1 line_1: ! question: 7 section: 1 line_1: All the data should be reducible using standard IRAF and STSDAS reduction line_2: packages. For absorption lines in which we resolve components, we line_3: have profile fitting routines available for subjective fits to the data, plus line_4: automatic routines which produce a best fit based on minimizing chi-squared. line_5: One of us (DVB) will work full time on the data reduction and analysis. ! question: 8 section: 1 line_1: ! question: 9 section: 1 line_1: FOC: Blades is a member of the FOC IDT and is involved in several imaging line_2: programs, but these are not related to this program. line_4: 2553---``The ISM of nearby galaxies using SN as probes'' (Blades---PI). line_5: Related Program. line_7: P2638---``The Near Ultraviolet spectrum of 0215+015.'' Not directly related. line_9: P2644: ``The Environments of Starburst Galaxies'' (C. Norman---PI). Related line_10: Program. line_12: P2563:``SINS: The Supernova Intensive Study'' (Kirshner---PI). Related Program. ! question: 10 section: 1 line_1: ! !end of general form text general_form_address: lname: BLADES fname: CHRIS category: PI inst: SPACE TELESCOPE SCIENCE INSTITUTE addr_1: 3700 SAN MARTIN DRIVE city: BALTIMORE state: MD zip: 21218 country: USA phone: 301-338-4805 telex: 6849101 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: 1341+258 descr_1: QSO pos_1: RA= 13H 43M 56.7S +/- 0.3", pos_2: DEC= +25D 38' 46.9" +/- 0.3" equinox: 2000.0 rv_or_z: Z=0.087 fluxnum_1: 1 fluxval_1: B=15.93 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: 1341+258 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 9S fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE=3 param_2: FAINT=300 req_1: CYCLE 1; req_2: ONBOARD ACQ FOR 2; req_3: DARK TIME ! linenum: 2.000 targname: 1341+258 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2850-2858 num_exp: 12 time_per_exp: 886S s_to_n: 10 s_to_n_time: 11520S fluxnum_1: 1 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=TWO param_3: STEP-PATT=DEF req_1: CYCLE 1 ! ! end of exposure logsheet ! No scan data records found