6070( 7) - 07/31/96 16:57 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6070 Version: 7 Check-in Date: 31-Jul-1996 17:53:38 1.Proposal Title: Interstellar Tin: Probing Galactic s- Process Elemental Enrichment ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: DAVID M. MEYER Northwestern University ------------------------------------------------------------------------------------ 6. Abstract We propose a study to obtain high quality interstellar abundance data for the heavy element Sn (Z = 50), an element produced mainly by s-process neutron capture in intermediate -to-low mass AGB stars, in a number of ISM sight lines known to sample a range of gas densities and depletions onto dust. Current (limited) data on Sn/H in a few dense ISM sight lines characteristic of large gas depletions onto dust show the abundance to be consistent with the solar value (i.e. no depletion onto dust). However, since Sn should be chemically similar to the other periodic table group IVA elements (i.e. C, Si, Ge, Sn, Pb) which share a common outer electron shell structure and which are depleted from solar by at least a factor 3, it should be somewhat depleted onto dust. Consequently, we believe that the apparent solar abundance reflects the fact that the ISM ( cosmic) abundance of Sn has increased since the formation of the solar system 4.5 billion years ago. This supposition is not unreasonable: observations of other heavy s-process elements in the atmospheres of some intermediate-to-low mass AGB stars show substantial enrichments and so we expect that some heavy s-process element enrichment of the ISM must have occurred. What makes the science proposed here significant is that it provides a great opportunity to determine the degree of enrichment, yielding important information on bulk s-process yields and cumulative injection of this material into the ISM over the past 4.5 billion years. ------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 2] Observations Description ------------------------ We propose to obtain Ech-A data in the LSA (2-4 samples/diode: STEP-PATT=6, 7) on the Sn II line at Lambda1400.44 Angstrom\\ toward six stars sampling a large range of f(H_2) values. We use the LSA to obtain maximum throughput (the 20\\ have no impact on the science goals). Basic target information is shown in the table below. Since accurate measures of the Sn line are desired (i.e. >= 5- Sigma detection limits), we require moderately high S/N values (400-600) at each of the 2 samples per diode. Accounting for guide star acquistion, target ACQ and ACQ/PEAKUP, and exposure overhead times, these values can be obtained in the remaining time in a single orbit (these estimates are based on the post- COSTAR LSA throughput data given the GHRS Cycle 5 Handbook). The exceptions are 15 Mon and Tau CMa which require exposuring during part of a second orbit to achieve the proper S/N. The required S/N values will be achieved through analysis of multiple grating position subexposures, obtained through the use of the FP-SPLIT option. We are experts in the development and use of the techniques for obtaining high S/N GHRS data (e.g. Cardelli & Ebbets 1994, ``Attaining High Signal-to-Noise Data with the Goddard High Resolution Spectrograph", Calibrating the Hubble Space Telescope, proceedings of a workshop held at STScI). begintableh begintabularccccccccc Name & & Spectral Type & & V & & Log H_total^a & & Log f(H_2)^b , Zeta Per (HD 24398)^\\# & & B1 Ib & & 2.87 & & 21.20 & & - 0.23 , beta^1 Sco (HD 144217A)^\\# & & B0.5 V & & 2.63 & & 21.14 & & -1.01 , Epsilon Ori (HD 37128) & & B0 Ia & & 1.70 & & 20.45 & & -3.58 , Kappa Ori (HD 38771)^\\# & & B0.5 Ia & & 2.09 & & 20.52 & & -4.54 , 15 Mon (HD 47839) & & O7 V & & 4.65 & & 20.40 & & -4.55 , Tau CMa (HD 57061) & & O9 II & & 4.40 & & 20.70 & & -5.22 , endtabular beginraggedright, ^alog of the total column density of hydrogen nuclei, H_total = 2H_2 + H I, ^blog of the fractional abundance of hydrogen nuclei in H_2, f(H_2) = 2H_2/H_total, endraggedright endtable The targets flagged with \\# are ones for which we have or will be obtaining data on Kr (as well as Ge and Mg) as part of our program GO-5473 (Zeta Per and Kappa Ori) and GTO 1162 (beta^1 Sco). Data for Ge and Mg for the other targets have been obtained from the data archives. This continuity strengthens the goals of the science here by providing Kr as a reference abundance (Kr should be undepleted) and Ge as an analogous depleted Group IVA element. To extend this continuity to Kr at low f(H_2) values, we are also requesting an Ech-A setup at Lambda1235 Angstrom\\ to obtain data on the Kr I line for Epsilon Ori and Tau CMa. In the case of the latter, this can be achieved by utilizing the time remaining in the second orbit. The entire program will take a total of 8 orbits. Real Time Justification ----------------------- None. None. Calibration Justification ------------------------- ustification Additional Comments ------------------- ------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD24398 STAR, B0-B2 III-I RA=03H 54M 07.9S +/- 0.03S, J2000 V = 2.87 DEC=+31D 53' 01.0" +/- 0.5" B-V = 0.12 Comments: target previously observed with ghrs-these coordinates come from the hst observing log 2 HD144217 STAR, B0-B2 V-IV RA=16H 05M 26.1S +/- 0.03S, DEC= J2000 V = 2.63 -19D 48' 19.0" +/- 0.5" B-V = -0.07 Comments: target previously observed with ghrs-these coordinates come from the hst observing log 3 HD37128 STAR, B0-B2 III-I RA=05H 36M 12.8S +/- 0.03S, DEC= J2000 V = 1.70 -01D 12' 06.9" +/- 0.5" B-V = -0.19 Comments: target previously observed with ghrs-these coordinates come from the hst observing log 4 HD38771 STAR, B0-B2 III-I RA=05H 47M 45.3S +/- 0.03S, DEC= J2000 V = 2.09 -09D 40' 11.0" +/- 0.5" B-V = -0.17 Comments: target previously observed with ghrs-these coordinates come from the hst observing log 5 HD47839 STAR, MAIN SEQUENCE O RA=06H 40M 58.7S +/- 0.03S, J2000 V = 4.65 DEC=+09D 53' 44.7" +/- 0.5" B-V = -0.25 Comments: target previously observed with ghrs-these coordinates come from the hst observing log 6 HD57061 STAR, SUPERGIANT O RA=07H 18M 42.4S +/- 0.03S, DEC= J2000 V = 4.40 -24D 57' 15.2" +/- 0.5" B-V = -0.15 Comments: target previously observed with ghrs-these coordinates come from the hst observing log 6070( 7) - 07/31/96 16:57 - [ 5] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD24398 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3 1 1.8 S ONBOARD ACQ FOR 2-3 Comments: expect a maximum of 3.6x10^5 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 2 HD24398 HRS ACCUM 2.0 ECH-A 1401.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 3 HD24398 HRS ACCUM 2.0 ECH-A 1402.2 FP-SPLIT=STD,STEP-PATT=6 1 10.56 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 6] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 HD144217 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3, 1 1.8 S ONBOARD ACQ FOR 5-7 LOCATE=EXTENDED Comments: expect a maximum of 2x10^6 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 5 HD144217 HRS ACCUM 2.0 ECH-A 1401.5 FP-SPLIT=STD,STEP-PATT=6 2 2.88 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6 HD144217 HRS ACCUM 2.0 ECH-A 1402.0 FP-SPLIT=STD,STEP-PATT=6 2 2.88 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 7 HD144217 HRS ACCUM 2.0 ECH-A 1402.5 FP-SPLIT=STD,STEP-PATT=6 2 2.88 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 7] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 8 HD37128 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3, 1 1.8 S ONBOARD ACQ FOR 9-12 LOCATE=EXTENDED Comments: expect a maximum of 4.6x10^6 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 9 HD37128 HRS ACCUM 2.0 ECH-A 1235.0 FP-SPLIT=STD,STEP-PATT=7 1 217.6 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 10 HD37128 HRS ACCUM 2.0 ECH-A 1236.0 FP-SPLIT=STD,STEP-PATT=7 1 217.6 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 11 HD37128 HRS ACCUM 2.0 ECH-A 1398.5 FP-SPLIT=STD,STEP-PATT=7 1 217.6 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 12 HD37128 HRS ACCUM 2.0 ECH-A 1399.5 FP-SPLIT=STD,STEP-PATT=7 1 217.6 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 8] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 HD38771 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3, 1 1.8 S ONBOARD ACQ FOR 14-16 LOCATE=EXTENDED Comments: expect a maximum of 3.2x10^6 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 14 HD38771 HRS ACCUM 2.0 ECH-A 1398.5 FP-SPLIT=STD,STEP-PATT=7 2 217.6 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 15 HD38771 HRS ACCUM 2.0 ECH-A 1399.5 FP-SPLIT=STD,STEP-PATT=7 1 326.4 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 16 HD38771 HRS ACCUM 2.0 ECH-A 1400.5 FP-SPLIT=STD,STEP-PATT=7 1 326.4 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 9] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 17 HD47839 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3 1 1.8 S ONBOARD ACQ FOR 18-22 Comments: expect a maximum of 6.6x10^5 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 18 HD47839 HRS ACCUM 2.0 ECH-A 1398.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 19 HD47839 HRS ACCUM 2.0 ECH-A 1399.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 20 HD47839 HRS ACCUM 2.0 ECH-A 1400.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 21 HD47839 HRS ACCUM 2.0 ECH-A 1401.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 22 HD47839 HRS ACCUM 2.0 ECH-A 1402.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 10] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 23 HD57061 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3 1 1.8 S ONBOARD ACQ FOR 24-28 Comments: expect a maximum of 5x10^5 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 24 HD57061 HRS ACCUM 2.0 ECH-A 1235.0 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 25 HD57061 HRS ACCUM 2.0 ECH-A 1236.0 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 26 HD57061 HRS ACCUM 2.0 ECH-A 1398.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 27 HD57061 HRS ACCUM 2.0 ECH-A 1399.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 28 HD57061 HRS ACCUM 2.0 ECH-A 1400.5 FP-SPLIT=STD,STEP-PATT=6 2 5.76 M Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 11] Visit: 07 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 HD38771 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN,SEARCH-SIZE=3, 1 1.8 S ONBOARD ACQ FOR 14-16 LOCATE=EXTENDED Comments: expect a maximum of 3.2x10^6 counts in a STEP-TIME = 0.2s provided BRIGHT=RETURN is used ------------------------------------------------------------------------------------------------------------------------------------ 14 HD38771 HRS ACCUM 2.0 ECH-A 1398.5 FP-SPLIT=STD,STEP-PATT=7 2 217.6 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 15 HD38771 HRS ACCUM 2.0 ECH-A 1399.5 FP-SPLIT=STD,STEP-PATT=7 1 326.4 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 16 HD38771 HRS ACCUM 2.0 ECH-A 1400.5 FP-SPLIT=STD,STEP-PATT=7 1 326.4 S Comments: MOD4 carrousel position should (must) be within 0.15 Angstroms of setup wavelength ------------------------------------------------------------------------------------------------------------------------------------ 6070( 7) - 07/31/96 16:57 - [ 12] Summary Form for Proposal 6070 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=3 STEP-PATT=6 FP-SPLIT=STD LOCATE=EXTENDED STEP-PATT=7 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2-3 ONBOARD ACQ FOR 5-7 ONBOARD ACQ FOR 9-12 ONBOARD ACQ FOR 14-16 ONBOARD ACQ FOR 18-22 ONBOARD ACQ FOR 24-28 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N1 ECH-A ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD24398 HD144217 HD37128 HD38771 HD47839 HD57061 ------------------------------------------------------------------------------------------------------------------------------------