! File: 4525C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:16:12:05 coverpage: title_1: THE ABSORPTION CROSS-SECTIONS OF NEARBY GALAXIES -CYC3 SUPPLEMENTAL sci_cat: QUASARS & AGN sci_subcat: QUASAR ABSORPTION proposal_for: GO pi_fname: CHRIS pi_lname: BLADES pi_inst: STSCI pi_country: USA hours_pri: 13.95 num_pri: 4 hrs: Y funds_length: 12 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: 410-338-4730 ! 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 or C IV absorption lines in the haloes of four 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. Our recent Cycle 1 discovery of MgII line_12: and C~IV absorption in the spectrum of Mrk~205 from the intervening galaxy line_13: NGC~4319 demonstrates that the technique is a powerful tool for investigating line_14: the interstellar medium of intervening galaxies and provides a stimulating line_15: comparision to the systems seen at higher redshifts. line_16: We were allocated 20 hours in Cycle 1, and 15 hours in Cycle 2. line_17: We now wish to conclude our GHRS survey in cycle 3. ! ! end of abstract general_form_proposers: lname: BLADES fname: CHRIS title: PI inst: STSCI country: USA esa: Y ! lname: BOWEN fname: DAVID mi: V. inst: STSCI country: USA esa: Y ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: ! question: 3 section: 1 line_1: line_2: We have selected 4 quasars based on their small separations from foreground line_3: galaxies, and on their brightness. QSOs with known UV fluxes are selected line_4: preferentially. Pairs in which the absorption line would be blended with local line_5: Galactic lines were excluded. An exhaustive search of the literature and line_6: examination of fields around QSOs with known UV flux shows that these are the line_7: brightest QSOs available with the smallest separations from galaxies. Details line_8: of the QSO-galaxy pairs selected are given below, except for 0026+129, whose line_9: observation is designed to complement a search for Mg~II in Cycle 2. line_11: We would use the G160M grating to observe C~IV and the G270M grating to search line_12: for Mg~II at the redshift of the galaxies listed below. The exception is line_13: 1116+215, whose flux is strong enough to permit observations with ECH-B. ! question: 3 section: 2 line_1: {\bf 0318$-$196 and NGC~1300:} Though the separation between the quasar and line_2: this nearby face-on galaxy is 44~kpc, the line-of-sight passes the disk within line_3: approximately three times the galaxy's optical radius, and within only twice line_4: the limit of the H~I distribution at a level of $5\times10^{19}$~cm$^{-2}$. line_5: Though the non-detection of Ca~II (Bowen~\etal\ 1991, Bothun, Margon \& Balick line_6: 1984) might be expected from a gas with an H~I column density less than this, line_7: we would expect Mg~II absorption from the disk and/or halo if there is no sharp line_8: cutoff in the H~I distribution. This pair was included in our successful Cycle line_9: 2 proposal, but uncertainty in the UV flux of the QSO forced us to omit the line_10: observation in Phase 2, despite the pairs obvious importance and suitability line_11: for this project. Since then, however, optim extraction and co-addition of line_12: spectra from the {\it IUE} archive by Lanzetta, Turnshek \& Sandoval (1992) line_13: demonstrates that the flux at 2800~\AA\ is quite sufficient to permit us to line_14: obtain high quality data, and we now consider this pair to be of highest line_15: priority. ! question: 3 section: 3 line_1: {\bf 3C232 and NGC 3067:} The spectrum of this famous QSO-galaxy pair was line_2: first shown to exhibit Ca~II absorption from the intervening galaxy by line_3: Boksenberg \& Sargent (1978). Recently, Carilli, van Gorkom \& Stocke (1989) line_4: showed that the absorption arose in gas distributed as a long tail extending line_5: from the center of the galaxy, across the QSO sightline. Extraction of IUE line_6: archive data by Kinney~\etal\ (1990) also showed Mg~II absorption line_7: (Bowen~\etal\ 1991a). line_9: Examination of the HST archive, and the planned Cycle 2 observations, reveals line_10: that no data were taken of this QSO in Cycle 1 and that only one group line_11: (Bachall \& Ratnatunga) will observe the sightline in Cycle 2 (augmentation), line_12: using the lower resolution of the {\it FOS}. As explained previously, data line_13: obtained with the {\it GHRS} will not only allow a more accurate determination line_14: of the physical conditions within the gas, but will also provide important line_15: information on its kinematics. We can then compare the velocity structure with line_16: that seen in similar resolution observations of Mg~II absorption at higher line_17: redshifts, and thereby ascertain whether similar galactic structures could be line_18: responsible for QSO absorption lines at earlier epochs. ! question: 3 section: 4 line_1: {\bf 1116+215 and Leo II:} The local dwarf galaxy Leo II lies 1.56 degrees from line_2: 1116+215. Despite the large angular separation, if the distance to Leo II is line_3: 230 kpc, then the sightline to the quasar intercepts the galaxy at only 6.2 line_4: kpc line_5: Zaritsky~\etal\ (1989) who found \vh$\:=\:70\pm4$~km/s , agreeing well with line_6: previous determinations (e.g. Olszewski, Peterson \& Aaronson 1986 and refs. line_7: therein) of $\simeq\:95\pm25$~km/s . The precision with which this number is line_8: known is important because the expected absorption from Leo II must not fall in line_9: the strong local Mg~II lines. This should not be a problem for two reasons: line_10: {\it a)} calculation of the absorption from gas corotating with the Galaxy line_11: shows that for an infinitely sized halo, the maximum corotation velocity is line_12: 60~km/s . For more reasonable scale heights ($\simeq\:2$~kpc) the maximum line_13: velocity is $<\:40$~km/s . Our three Cycle 1 observations show that the line_14: distribution of Mg~II components follows Galactic corotation closely. {\it b)} line_15: The QSO is bright enough to use ECH-B for the Mg~II absorption. This will not line_16: only give us sufficient resolution to resolve any absorption from Leo~II but line_17: will permit one of the first observations of absorption from the Milky Way line_18: towards an {\it extragalactic} sightline (that is, through the entire length of line_19: the halo) using ECH-B. ! question: 4 section: 1 line_1: The study of absorption by low-redshift galactic haloes in the {\it 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 $z\:\apg\:0.2$ and C~IV above $z\:\apg\: line_6: 1.2$ in the optical. These are therefore only accessible at lower redshifts line_7: with the {\it International Ultraviolet Explorer (IUE)}. {\it IUE} has a small line_8: aperture which permits detection of only strong ($1-2$~\AA ) lines in the line_9: brightest quasar spectra and is unsuitable for detecting lines at the line_10: equivalent width limits (0.25~\AA ) of the higher redshift absorption line line_11: surveys. The {\it GHRS} plus {\it HST} is ideal for this study. The line_12: instrument is sensitive enough to detect weak Mg~II and C~IV lines in bright line_13: quasars, and, with the intermediate-dispersion gratings, data can be obtained line_14: with a resolution which discerns the large-scale velocity structure of the line_15: absorption-line profiles. This in turn permits a more accurate determination of line_16: column densities and doppler parameters, and leads to a more detailed analysis line_17: of the chemical, ionization and kinematics of the absorbing gas. For these two line_18: reasons, the {\it GHRS} is more suitable for studying the physics of galactic line_19: haloes than the {\it FOS}. ! question: 4 section: 2 line_1: All our exposure times are aimed at obtaining a uniform signal-to-noise line_2: ratio---and hence equivalent width limit---for all the spectra. We have adopted line_3: a background count of 0.012~\cds\ for Detector 2 and set all the exposure line_4: times to reach a signal-to-noise---for half-stepped data---of 7 per pixel for line_5: Mg~II lines and 5 per pixel for C~IV. The one exception is 1116+215, whose line_6: flux is high enough for us to reach a S/N of 9 with ECH-B in 1.6 hours. From line_7: our experience with Cycle 1 and 2 {\it GHRS} data, we have found these values line_8: to be sufficient to allow fitting of theoretical absorption line profiles. If line_9: the resolution of the spectrograph can be characterised by the FWHM of the PSF line_10: given by Duncan (1992), about 2.3 pixels for half-stepped data, then we achieve line_11: resolutions of $\simeq\:15$~km/s with the 270M and 20~km/s with the 160M line_12: grating. We then reach equivalent width limits of $\simeq\:30$~m\AA\ at Mg~II line_13: and at C~IV ($2\sigma$), and will be able to resolve components within the line_14: absorption line. Where the line is weak or undetected, rebinning the spectra line_15: from the G270M grating would improve the equivalent width limit by line_16: $\approx\:15$\%. line_18: We base our exposure times on the sensitivity curves in v3.0 of the ``{\it GHRS} line_19: Instrument Handbook''. The flux is known for all of our objects line_20: from {\it IUE} archive data compiled by Kinney~\etal\ (1991) or by Lanzetta, line_21: Turnshek \& Sandoval (1992). The accuracy of the anticipated count rates also line_22: depends on the variability of the quasar, but we expect variations of $< \pm 2$ line_23: based on the the values found by Kinney~\etal . ! question: 5 section: 1 line_1: We expect any MgII absorption from LeoII toward 1116+215 to be just resolved line_2: from the local MgII absorption. Current estimates of the velocities of stars line_3: within the dwarf are very precise, of order of a few km/s, and we would wish to line_4: match any absorption features seen with these velocities. We therefore require line_5: a wavelength accuracy better than the $\pm1$ diode (half a resolution element) line_6: normally available, and will need spectral calibration lamps taken after the line_7: exposure, as suggested in the {\it GHRS} manual. ! question: 6 section: 1 line_1: None ! 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: ! question: 10 section: 1 line_1: ! !end of general form text general_form_address: lname: BLADES fname: CHRIS category: PI inst: STScI addr_1: 3700 SAN MARTIN DRIVE city: BALTIMORE state: MD zip: 21218 country: USA phone: 410-338-4805 telex: blades@stsci.edu ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: 0318-196 descr_1: E,313,314 pos_1: RA= 3H 20M 21.15S +/- 0.3", pos_2: DEC= -19D 26' 32" +/- 0.3", pos_3: PLATE-ID=014E equinox: 2000 rv_or_z: Z=0.104 fluxnum_1: 1 fluxval_1: V=14.9 fluxnum_2: 2 fluxval_2: F-CONT(2800)=4E-15 ! targnum: 2 name_1: 0955+326 descr_1: E,313,314 pos_1: RA= 9H 58M 21.03S +/- 0.3", pos_2: DEC= 32D 24' 1.5" +/- 0.3", pos_3: PLATE-ID=01RS equinox: 2000 rv_or_z: Z=0.533 fluxnum_1: 1 fluxval_1: V=15.8 fluxnum_2: 2 fluxval_2: F-CONT(2800)=5E-15 ! targnum: 3 name_1: 0026+129 descr_1: E,313,314 pos_1: RA= 0H29M13.75S +/- 0.3", pos_2: DEC= 13D16'3.7" +/- 0.3", pos_3: PLATE-ID=028X equinox: 2000 rv_or_z: Z=0.142 fluxnum_1: 1 fluxval_1: V=15.4 fluxnum_2: 2 fluxval_2: F-CONT(1500)=1.8E-14 ! targnum: 4 name_1: 1116+215 descr_1: E,313,314 pos_1: RA= 11H 19M 8.72S +/- 0.3", pos_2: DEC= 21D 19' 18.1" +/- 0.3", pos_3: PLATE-ID=01TL equinox: 2000 rv_or_z: Z=0.177 fluxnum_1: 1 fluxval_1: V=15.0 fluxnum_2: 2 fluxval_2: F-CONT(2800)=3.0E-14 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: 0318-196 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 3; req_2: ONBOARD ACQ FOR 2; req_3: DARK TIME ! linenum: 2.000 targname: 0318-196 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2807.3 num_exp: 9 time_per_exp: 1080S s_to_n: 7 s_to_n_time: 9720S fluxnum_1: 2 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=FOUR param_3: STEP-PATT=4 req_1: CYCLE 3 ! linenum: 3.000 targname: 0955+326 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 3; req_2: ONBOARD ACQ FOR 4; req_3: DARK TIME ! linenum: 4.000 targname: 0955+326 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2807.1 num_exp: 6 time_per_exp: 1080S s_to_n: 7 s_to_n_time: 6480S fluxnum_1: 2 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=FOUR param_3: STEP-PATT=DEF req_1: CYCLE 3 ! linenum: 5.000 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 3; req_2: ONBOARD ACQ FOR 6; req_3: DARK TIME ! linenum: 6.000 targname: 0026+129 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1557.0 num_exp: 12 time_per_exp: 1170S s_to_n: 5 s_to_n_time: 3.9H fluxnum_1: 2 priority: 1 param_1: COMB=FOUR param_2: FP-SPLIT=FOUR param_3: STEP-PATT=4 req_1: CYCLE 3 ! linenum: 7.000 targname: 1116+215 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 3; req_2: ONBOARD ACQ FOR 6; req_3: DARK TIME ! linenum: 8.000 targname: 1116+215 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-B wavelength: 2799.6 num_exp: 5 time_per_exp: 1166S s_to_n: 9.1 s_to_n_time: 5832S fluxnum_1: 2 priority: 2 param_1: COMB=FOUR param_2: FP-SPLIT=FOUR param_3: STEP-PATT=6 req_1: CYCLE 3 ! linenum: 9.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: ECH-B wavelength: 2799.6 num_exp: 1 time_per_exp: 60S priority: 2 param_1: COMB=FOUR param_2: FP-SPLIT=FOUR param_3: STEP-PATT=6 req_1: CALIB FOR 8.0; req_2: SEQ 8.0-9.0 NO GAP; req_3: CYCLE 3 ! ! end of exposure logsheet ! No scan data records found