Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4217c Report Date: 09-May-96:19:26 Version: ********** Check-in Date: ********** 1.Proposal Title: THE ABSORPTION CROSS-SECTIONS OF NEARBY GALAXIES--- REPEAT FOR HOPR#56 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID QUASARS & AGN RPT/GO 2553 Sub Category QUASAR ABSORPTION ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Chris Blades SPACE TELESCOPE SCIENCE INST ------------------------------------------------------------------------------------ 7. Abstract We wish to examine the hypothesis that low-redshift galaxies are surrounded by extended gaseous haloes and disks. Specifically, we propose using the GHRS to search for Mg II and C IV absorption lines in the haloes of low-redshift galaxies lying fortuitously in front of background quasars. We aim to reach sensitive equivalent widths limits of 60 mA and 40 mA (2 sigma) for each of the ions, and hence to infer the chemical, ionization and kinematic conditions within the absorbing gas by accurately measuring column densities, doppler parameters, and the large-scale multicomponent structure of the lines. Comparisons of the absorption in nearby galaxies with the lines seen at higher redshifts in QSO spectra should help settle the issue of how the metal-line systems originate. The recent discovery of Ly alpha absorption at very low redshift in 3C 273 with the GHRS makes our proposal timely and relevant. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.20 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4217c PI: Chris Blades Proposal Title: THE ABSORPTION CROSS-SECTIONS OF NEARBY GALAXIES--- REPEAT FOR HOPR#56 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Chris Blades SPACE TELESCOPE SCIENCE U.S.A. INSTITUTE David V. Bowen SPACE TELESCOPE SCIENCE U.S.A. X INSTITUTE Max Pettini ROYAL GREENWICH OBSERVATORY U.K. X ------------------------------------------------------------------------------------ 2. Scientific Justification. ------------------------------------------------------------------------------------ 3. Description of proposed observations. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The study of absorption by low-redshift galactic haloes in the same ions observed at higher redshifts is arguably the most important step in understanding the nature of the absorbing galaxies in the early universe. Mg~II lines can only be observed for z > 0.2 and C~IV above z > 1.2 in the optical. These are therefore only accessible at lower redshifts with the (IUE). IUE has a small aperture which permits detection of only strong ($1-2$~\AA ) lines in the brightest quasar spectra and is unsuitable for detecting lines at the equivalent width limits (0.25~\AA ) of the higher redshift absorption line surveys. The GHRS plus HST is ideal for this study. The sensitivity of the instrument is high enough to detect weak Mg~II lines in bright quasars, and, with the intermediate- dispersion gratings, data can be obtained with a resolution which discerns the large-scale velocity structure of the absorption-line profiles. This in turn permits a more accurate determination of column densities and doppler parameters, and leads to a more detailed analysis of the chemical, ionization and kinematics of the absorbing gas. For these two reasons, the GHRS is more suitable for studying the physics of galactic haloes than the FOS. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. All the data should be reducible using standard IRAF and STSDAS reduction packages. For absorption lines in which we resolve components, we have profile fitting routines available for subjective fits to the data, plus automatic routines which produce a best fit based on minimizing chi-squared. One of us (DVB) will work full time on the data reduction and analysis. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. ------------------------------------------------------------------------------------ 9. Description of previous HST work. FOC: Blades is a member of the FOC IDT and is involved in several imaging programs, but these are not related to this program. 2553---``The ISM of nearby galaxies using SN as probes'' (Blades---PI). Related Program. P2638---``The Near Ultraviolet spectrum of 0215+015.'' Not directly related. P2644: ``The Environments of Starburst Galaxies'' (C. Norman---PI). Related Program. P2563:``SINS: The Supernova Intensive Study'' (Kirshner---PI). Related Program. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Page 3 ------------------------------------------------------------------------------------ 11. Address Information Name: CHRIS BLADES Category: PI Institution: SPACE TELESCOPE SCIENCE INSTITUTE Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 301-338-4805 Telex (or e-mail): 6849101 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 4217c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 1341+258 QSO RA= 13H 43M 56.7S +/- 0.3", 2000.0 Z=0.087 1 B=15.93 DEC= +25D 38' 46.9" +/- 0.3" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4217c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 1341+258 HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=3 1 9S 1 1 CYCLE 1 FAINT=300 ONBOARD ACQ FOR 2 DARK TIME ------------------------------------------------------------------------------------------------------------------------------------ 2 1341+258 HRS ACCUM 2.0 G270M 2850- COMB=FOUR 12 886S 10 1 1 CYCLE 1 2858 FP-SPLIT=TWO 11520S STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4217c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE=3 FAINT=300 COMB=FOUR FP-SPLIT=TWO STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ Proposal for RPT/GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.20 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QUASARS & AGN ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category QUASAR ABSORPTION ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 1; ONBOARD ACQ FOR 2; DARK TIME CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G270M ------------------------------------------------------------------------------------------------------------------------------------ Target Names 1341+258 ------------------------------------------------------------------------------------------------------------------------------------