! File: 3755C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:18:27:46 coverpage: title_1: THE ABSORPTION CROSS-SECTIONS OF NEARBY GALAXIES sci_cat: QUASARS & AGN sci_subcat: QUASAR ABSORPTION proposal_for: GO pi_fname: CHRIS pi_lname: BLADES pi_inst: SPACE TELESCOPE SCIENCE INSTITUTE hours_pri: 15.03 num_pri: 3 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: We have selected 5 quasars based on their small separations from foreground line_2: galaxies and on their brightness. Pairs in which the absorption line would be line_3: blended with local Galactic lines were excluded. One of these quasars line_4: (0219+428) has been observed in Cycle~1. In this case, we wish to continue the line_5: observations to realise uniform equivalent width limits. We wish to use the line_6: G270M grating to search for Mg~II at the redshift of the galaxies listed line_7: below. line_9: We have adopted a background count of 0.012~\cds\ for Detector 2 and set all line_10: the exposure times to reach a signal-to-noise of 5-7. With the resolving power line_11: of the GHRS gratings reduced to half the pre-launch values we will achieve a line_12: resolution of 10~\Ks\ with the 270M grating. A signal-to-noise of 7 at these line_13: resolutions would give an equivalent width limit of $\simeq\:60$~m\AA\ at Mg~II line_14: and resolve components within the absorption line. line_16: Our exposure times are based on the sensitivity curves in the GHRS manual. The line_17: flux is known for 2 of the objects at the wavelength of the ion we wish to line_18: observe. The anticipated count rates also depends on the variability line_19: of the quasar, but we expect variations of < +/- 2 based on the the values line_20: found by Kinney et al. No IUE spectra exist for 0318-196 (B=15.9) or 0031-707 line_21: (V=15.5). To estimate the count rate we have compared the $B$ magnitudes of line_22: QSOs with similar redshifts in Kinney et al.'s atlas with the flux at 2800~\AA ! 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: 0026+129 descr_1: E,313,314 pos_1: RA= 0H 29M 13.83S +/- 0.3", pos_2: DEC= +13D 16' 2.4" +/- 0.3" equinox: 2000.0 rv_or_z: Z=0.142 comment_1: PLATE-ID=XE465 fluxnum_1: 1 fluxval_1: B=14.6 fluxnum_2: 2 fluxval_2: F-CONT(2800) = 0.5E-14 ! targnum: 2 name_1: 0637-752 descr_1: E,313,314 pos_1: RA= 06H 35M 46.764S +/- 0.6", pos_2: DEC= -75D 16' 16.72" +/- 0.6" equinox: 2000.0 rv_or_z: Z=0.656 fluxnum_1: 1 fluxval_1: B=15.75 fluxnum_2: 2 fluxval_2: F-CONT(2810) = 3.0E-15 ! targnum: 3 name_1: 1543+489 descr_1: E,313,314 pos_1: RA= 15H 45M 30.3S +/- 0.6", pos_2: DEC= +48D 46' 7.9" +/- 0.6" equinox: 2000.0 rv_or_z: Z=0.40 fluxnum_1: 1 fluxval_1: B=16.05 fluxnum_2: 2 fluxval_2: F-CONT(3000) = 3.2E-15 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: 0026+129 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: BRIGHT=RETURN req_1: CYCLE 2; req_2: ONBOARD ACQ FOR 2; req_3: DARK TIME ! linenum: 2.000 targname: 0026+129 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2796-2820 num_exp: 6 time_per_exp: 900S s_to_n: 6.1 s_to_n_time: 5400S fluxnum_1: 1 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=TWO param_3: STEP-PATT=DEF req_1: CYCLE 2 ! linenum: 3.000 targname: 0637-752 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 9S fluxnum_1: 2 priority: 1 param_1: SEARCH-SIZE=3 param_2: BRIGHT=RETURN req_1: CYCLE 2; req_2: ONBOARD ACQ FOR 4; req_3: DARK TIME ! linenum: 4.000 targname: 0637-752 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2796-2810 num_exp: 14 time_per_exp: 900S s_to_n: 6.4 s_to_n_time: 12600S fluxnum_1: 1 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=TWO param_3: STEP-PATT=DEF req_1: CYCLE 2 ! linenum: 5.000 targname: 1543+489 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 9S fluxnum_1: 2 priority: 1 param_1: SEARCH-SIZE=3 param_2: BRIGHT=RETURN req_1: CYCLE 2; req_2: ONBOARD ACQ FOR 6; req_3: DARK TIME ! linenum: 6.000 targname: 1543+489 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 3005-3014 num_exp: 25 time_per_exp: 870S s_to_n: 5.6 s_to_n_time: 21750S fluxnum_1: 1 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=TWO param_3: STEP-PATT=DEF req_1: CYCLE 2 ! ! end of exposure logsheet ! No scan data records found