! File: 4239C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:18:41:04 coverpage: title_1: ABUNDANCE ENHANCEMENTS IN HALO GAS -- RPT FOR HOPR#64 sci_cat: INTERSTELLAR MEDIUM proposal_for: RPT/GO cont_id: 2348 pi_title: DR. pi_fname: EDWARD pi_mi: B. pi_lname: JENKINS pi_inst: PRINCETON UNIVERSITY pi_country: USA pi_phone: 609-258-3826 keywords_1: HALO, SUPERNOVA REMNANT, ABUNDANCES, GAS hours_pri: 12.00 num_pri: 7 hrs: X funds_amount: 47000 funds_length: 12 funds_date: SEP-91 pi_position: SR. RES. ASTRONOMER off_fname: ALLEN off_mi: J. off_lname: SINISGALLI off_title: DIRECTOR off_inst: PRINCETON UNIVERSITY off_addr_1: OFFICE OF RESEARCH AND PROJECT ADMINISTRATION off_addr_2: 5 NEW SOUTH BUILDING off_city: PRINCETON off_state: NJ off_zip: 08544 off_country: USA ! end of coverpage abstract: line_1: We propose to use HRS in its moderate resolution mode to examine interstellar line_2: absorption lines in the spectra of stars situated ~1 kpc or more from the line_3: galactic plane. We will compare Fe II, S II, Si II and Al II to see if their line_4: relative abundances differ from ordinary interstellar gas, as indicated by a line_5: conservative interpretation of some IUE data. We will equate possible line_6: abundance enhancements in halo gas, if they are indeed real, with element line_7: replenishments found in shocked gases in the plane (associated with the Vela line_8: SNR) to see if the pattern from element to element differs from that resulting line_9: from the destruction of grains. This differentiation will indicate whether the line_10: principal enhancements are from grain evaporation as the gas is ejected from line_11: the plane, or whether element injection from Type I supernovae plays an line_12: important role. ! ! end of abstract general_form_proposers: lname: JENKINS fname: EDWARD title: P.I. mi: B. inst: PRINCETON UNIVERSITY country: USA ! lname: WALLERSTEIN fname: GEORGE inst: WASHINGTON, UNIVERSITY OF country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: A SHORT DESCRIPTION OF THE PROPOSED OBSERVATIONS line_3: For all of the 7 stars covered by this proposal, we intend to observe the line_4: following lines using the GHRS G160M grating. Our goal is to achieve a line_5: signal-to-noise ratio of approximately 50 for any diode which is exposed to a line_6: full continuum level. line_8: ION WAVELENGTH(A) LOG (F LAMBDA) COMMENTS line_10: S II 1250.586 0.83 these two lines can be line_12: Fe II 1608.456 2.55 line_13: Al II 1670.784 3.50 line_14: Al III 1854.720 2.70 these two lines can be line_16: P II 1301.878 1.35 Bonus line line_17: O I 1302.169 1.80 Bonus line line_18: Si II 1304.369 2.28 Strong line to match Al II line_19: Si II 1808.003 0.83 Weak line to match S II ! question: 3 section: 2 line_1: The two lines of S II can be observed simultaneously. The Fe II line may be line_2: observed at the same carrousel setting as the S II lines. The singly ionized line_3: species are the dominant ionization stages and represent the primary line_4: information on abundances. In addition, we'll observe doubly ionized Al to line_5: check that these elements are not appreciably ionized more than once by an line_6: extragalactic radiation flux below the Lyman limit. ! question: 4 section: 1 line_1: THE NEED FOR CAPABILITIES OF HST line_3: Lines from the ground states of the ions discussed in this proposal are found line_4: only in the ultraviolet. An extensive investigation of high-resolution line_5: spectra in the IUE archives revealed tantalizing but rather crude line_6: indications that indeed there is element enrichment in the halo gas. line_7: Unfortunately, interstellar absorption lines which are strong enough to line_8: measure reliably with IUE almost always are badly saturated. line_9: Correcting for the saturation using curve-of-growth techniques is of dubious line_10: value. If one has good signal-to-noise recordings at a high enough line_11: resolution to completely resolve the velocity structure of a line, column line_12: densities may be derived by integrating the optical depth over velocity line_13: intervals where the line is not heavily saturated. ! question: 5 section: 1 line_1: All of our stars except HD120086 (target 6) have line_2: published fluxes at 1565A available from the TD-1 survey. To obtain fluxes line_3: at wavelengths that will be covered by this program, relative to the flux at line_4: 1565A, we used spectra in the IUE spectral atlas for stars of similar line_5: spectral type. There are no large reddening corrections to apply to our line_6: stars, since all values of E(B-V) are of order or less than 0.1. line_8: To observe wavelength intervals centered at 1252.5, 1318.5, 1619.0, 1667.0, line_9: 1817.5, and 1857.0 A at a signal-to-noise ratio of 50:1 per diode, we line_10: expect that an observing time given by line_12: t_(-10) = sum{2.50e13 / [(S(lambda) F / F_1560) 0.94]} line_13: = 29715 seconds line_15: will be required to cover the 6 wavelength intervals for a star with F(1560) line_16: = 10^{-10} erg cm^{-2} s^{-1} A^{-1}. We used values of S(lambda) tabulated line_17: in an update on instrument performance dated 6 May 1991 (p. 8 of GHRS memo). line_18: These numbers, in turn, were multiplied by the SSA loss factor of 0.25. line_19: The factor 0.94 results from our planning to use Substep pattern #5. ! question: 5 section: 2 line_1: For the 7 stars in our program our total observing time T = t(-10) line_2: sum{[F(1565)X10^10]^-1} = 533 minutes. Since we need to observe each star line_3: only once, the additional spacecraft time is only 7 stars X (15 min line_4: acquisision + 6 min set-up) = 147 min. ! question: 7 section: 1 line_1: PLANS FOR DATA REDUCTION AND ANALYSIS line_3: We think that it is very likely that the capabilities of the SDAS/IRAF line_4: analysis system will satisfy our reduction requirements. We intend to line_5: familiarize ourselves with this system during one or more visits to the STScI line_6: in the early phases of the program. If it is not too difficult, we may try line_7: to install this software on our own computer systems and continue to work on line_8: our data at our home institutions. If this is not feasible, we will complete line_9: our reductions during subsequent visits to the STScI. line_11: Present systems at our home institutions are a VAX/8350, Sun and Convex at line_12: Princeton, and a VAX/780 and MicroVAX cluster at the University of line_13: Washington. IRAF is currently up and running at the University of line_14: Washington. ! question: 10 section: 1 line_1: VAX/8350, Sun-4 and Convex computers at Princeton line_2: VAX/780, and MicroVAX cluster at the University of Washington ! !end of general form text general_form_address: lname: JENKINS fname: EDWARD mi: B. title: DR. category: PI inst: PRINCETON UNIVERSITY addr_1: DEPT. OF ASTROPHYSICAL SCI. addr_2: PEYTON HALL; IVY LANE city: PRINCETON state: NJ zip: 08544 country: USA ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: HD177566 descr_1: STAR; TYPE=B1 III pos_1: RA = 19H 03M 36.8S +/- 1." , pos_2: DEC = -41D 47' 57" +/- 1" equinox: 1950 rv_or_z: V=-131 fluxnum_1: 1 fluxval_1: V = 10.2, TYPE=B1 III fluxnum_2: 2 fluxval_2: F-CONT(1565)=1.2+/-.1E-11 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.010 sequence_1: DEFINE SC1 targname: # config: HRS opmode: ACCUM aperture: 0.25 sp_element: G160M wavelength: 1252.5 num_exp: 1 time_per_exp: 110S s_to_n: # fluxnum_1: 2 priority: 1 param_1: STEP-PATT=4 param_2: FP-SPLIT=STD comment_1: COVERAGE: S II 1250.586 ! linenum: 1.020 sequence_1: ^ targname: # config: ^ opmode: ^ aperture: ^ sp_element: G160M wavelength: 1318.5 num_exp: 1 time_per_exp: 110S s_to_n: # fluxnum_1: ^ priority: 1 param_1: ^ param_2: ^ comment_1: COVERAGE: SI II 1304.369 ! linenum: 1.030 sequence_1: ^ targname: # config: ^ opmode: ^ aperture: ^ sp_element: G160M wavelength: 1619.0 num_exp: 2 time_per_exp: 110S s_to_n: # s_to_n_time: 220S fluxnum_1: ^ priority: 2 param_1: ^ param_2: ^ comment_1: COVERAGE: FE II 1608.456 ! linenum: 1.040 sequence_1: ^ targname: # config: ^ opmode: ^ aperture: ^ sp_element: G160M wavelength: 1667.0 num_exp: 2 time_per_exp: 110S s_to_n: # s_to_n_time: 220S fluxnum_1: ^ priority: 2 param_1: ^ param_2: ^ comment_1: COVERAGE: AL II 1670.784 ! linenum: 1.050 sequence_1: ^ targname: # config: ^ opmode: ^ aperture: ^ sp_element: G160M wavelength: 1817.5 num_exp: 2 time_per_exp: 110S s_to_n: # s_to_n_time: 220S fluxnum_1: ^ priority: 2 param_1: ^ param_2: ^ comment_1: COVERAGE: SI II 1808.003 ! linenum: 1.060 sequence_1: ^ targname: # config: ^ opmode: ^ aperture: ^ sp_element: G160M wavelength: 1857.0 num_exp: 2 time_per_exp: 110S s_to_n: # s_to_n_time: 220S fluxnum_1: ^ priority: 2 param_1: ^ param_2: ^ comment_1: COVERAGE: AL III 1854.720 comment_2: 1862.795 ! linenum: 5.000 targname: HD177566 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 5S fluxnum_1: 1 priority: 1 param_1: FAINT=5000 param_2: SEARCH-SIZE=5 param_3: BRIGHT=65535 req_1: ONBOARD ACQ FOR 5.01; req_2: CYCLE 1 / 5.00-5.02; comment_1: COMPUTED RATE = 104K C/S. ! linenum: 5.010 targname: HD177566 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 9.2S fluxnum_1: 1 priority: 1 req_1: ONBOARD ACQ FOR 5.02 ! linenum: 5.020 sequence_1: USE SC1 targname: HD177566 time_per_exp: X4.0 s_to_n: 33.3 ! ! end of exposure logsheet ! No scan data records found