6575( 5) - 07/12/96 17:24 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6575 Version: 5 Check-in Date: 12-Jul-1996 17:19:41 1.Proposal Title: Observations of Interstellar Clouds in the Galactic Halo ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle INTERSTELLAR MEDIUM GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: EDWARD L. FITZPATRICK PRINCETON UNIVERSITY OBSERVATORY ------------------------------------------------------------------------------------ 6. Abstract In this proposal I am asking for 10 orbits to obtain high- resolution GHRS echelle spectra of interstellar UV absorption lines towards 2 stars located in the Galactic halo, HD119608 and HD167756. The analysis proposed for these data represents a continuation of an investigation begun using GTO data by the P.I. and L. Spitzer. The unique combination of high spectral resolution and high photometric precision available with the GHRS allow a detailed ``component analysis'' to be applied to the wide array of UV absorption features present in the 1200-- 3000 Angstrom region. The goal of the program is to determine the physical properties of individual interstellar clouds in the halo, to provide a firm observational foundation for theoretical models of the various processes which shape the ISM in the halo. The particular issues I will focus on in analyzing these data are the elemental abundances & depletions in the halo clouds, the physical conditions (temperatures and n_e), the relationship between warm, ionized halo gas and neutral gas, and the distributions of the highly-ionized species relative the low ionization stage species. Results obtained so far demonstrate the power of the GHRS data and this component analysis to address fundamental issues about the structure and origin of the ISM. ------------------------------------------------------------------------------------ 6575( 5) - 07/12/96 17:24 - [ 2] Observations Description ------------------------ The observations proposed here for HD119608 and HD167756 consist of GHRS echelle spectra taken at a number of distinct wavelength setup positions, chosen to include important interstellar absorption features. Data will be obtained with the stellar image in the Small Science Aperture to achieve the best possible spectral resolution (~3.5 km/s). The FP-SPLIT observing strategy will be used (FP-SPLIT=DSFOUR, COMB=FOUR, STEP-PATT=DEF) to minimize the effects of fixed-pattern noise, yielding spectral sampled every 1/4-diode. Eleven GHRS setup positions are requested for HD 119608, 4 with ECH-A and 7 with ECH-B, requiring 7 orbits. The ECH-A observations are centered approximately at 1240 A, 1252 A, 1335 A, and 1561 A, have total exposute times between 22 and 47 minutes (designed to obtain spectra with S/N levels of about 23:1), and include the species C I, C II, N V, Mg II, and S II. The ECH-B positions are centered at approximately 1806 A, 2026 A, 2060 A, 2260 A, 2374 A, 2603 A, and 2852 A, have exposure times bwtween 13 and 33 minutes (to obtain S/N values of 22:1 to 40:1), and include the species Mg I, Si II, Mn II, Cr II, Fe II, and Zn II. Seven GHRS setup positions are requested for HD167756, 3 with ECH-A and 4 with ECH-B, requiring 3 orbits. The ECH-A observations are centered approximately at 1192 A, 1252 A, and 1561 A, have total exposute times between 7 and 18 minutes (designed to obtain spectra with S/N levels of about 38:1), and include the species C I, Si II, S III,and S II. The ECH-B positions are centered at approximately 1806 A, 2260 A, 2603 A, and 2852 A, have exposure times bwtween 4 and 20 minutes (to obtain S/N values of about to 45:1), and include the species Mg I, Si II, Mn II, and Fe II. Real Time Justification ----------------------- There are no real-time scheduling requirements for this program. Calibration Justification ------------------------- There are no special calibrations required for this program. Additional Comments ------------------- There are no additional comments. ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: , ------------------------------------------------------------------------------------ 6575( 5) - 07/12/96 17:24 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD119608 STAR, B0-B2 III-I RA=13H 44M 31.29S +/- 0.2S,DEC=- 2000 F-CONT(1300)=4.0+/-0.5e-11 17D 56' 13.5" +/- 0.2" V = 7.53+/-0.03 B-V = -0.06+/-0.02 TYPE=B1IB Comments: Coordinates are from Hipparcos INCA Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0 0.0 0.0 2 HD167756 STAR, B0-B2 III-I RA=18H 18M 40.19S +/- 0.1S,DEC=- 2000 F-CONT(1300)=3.2+/-0.5e-10 42D 17' 18.6" +/- 0.1" V = 6.30+/-0.02 B-V = -0.13+/-0.01 TYPE=B0.5IA Comments: Coordinates are from Hipparcos INCA Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0 0.0 0.0 6575( 5) - 07/12/96 17:24 - [ 4] 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 HD119608 HRS ACQ 2.0 MIRROR-N1 1 1.8 S ONBOARD ACQ FOR 002 Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 2 HD119608 HRS ACQ/PEA 0.25 MIRROR-N1 1 5.0 S ONBOARD ACQ FOR 005-021 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 5 HD119608 HRS ACCUM 0.25 ECH-A 1241.00 FP-SPLIT=DSFOUR,STEP-PATT=DEF 2 870.4 S ------------------------------------------------------------------------------------------------------------------------------------ 6 HD119608 HRS ACCUM 0.25 ECH-A 1252.89 FP-SPLIT=DSFOUR,STEP-PATT=DEF 2 1196.8 ------------------------------------------------------------------------------------------------------------------------------------ 9 HD119608 HRS ACCUM 0.25 ECH-A 1335.32 FP-SPLIT=DSFOUR,STEP-PATT=DEF 2 870.4 S ------------------------------------------------------------------------------------------------------------------------------------ 10 HD119608 HRS ACCUM 0.25 ECH-A 1561.1 FP-SPLIT=DSFOUR,STEP-PATT=DEF 2 1414.4 ------------------------------------------------------------------------------------------------------------------------------------ 15 HD119608 HRS ACCUM 0.25 ECH-B 1807.93 FP-SPLIT=DSFOUR,STEP-PATT=DEF 2 979.2 S ------------------------------------------------------------------------------------------------------------------------------------ 16 HD119608 HRS ACCUM 0.25 ECH-B 2027.00 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 870.4 S ------------------------------------------------------------------------------------------------------------------------------------ 17 HD119608 HRS ACCUM 0.25 ECH-B 2059.77 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 870.4 S ------------------------------------------------------------------------------------------------------------------------------------ 18 HD119608 HRS ACCUM 0.25 ECH-B 2261.12 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 870.4 S ------------------------------------------------------------------------------------------------------------------------------------ 19 HD119608 HRS ACCUM 0.25 ECH-B 2371.36 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 870.4 S ------------------------------------------------------------------------------------------------------------------------------------ 20 HD119608 HRS ACCUM 0.25 ECH-B 2603.71 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 761.6 S ------------------------------------------------------------------------------------------------------------------------------------ 21 HD119608 HRS ACCUM 0.25 ECH-B 2852 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 652.8 S ------------------------------------------------------------------------------------------------------------------------------------ 6575( 5) - 07/12/96 17:24 - [ 5] 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD167756 HRS ACQ 2.0 MIRROR-N1 1 1.8 S ONBOARD ACQ FOR 002 Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 2 HD167756 HRS ACQ/PEA 0.25 MIRROR-N1 1 5.0 S ONBOARD ACQ FOR 005-011 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 5 HD167756 HRS ACCUM 0.25 ECH-A 1192.53 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 1088.0 ------------------------------------------------------------------------------------------------------------------------------------ 6 HD167756 HRS ACCUM 0.25 ECH-A 1252.89 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 761.6 S ------------------------------------------------------------------------------------------------------------------------------------ 7 HD167756 HRS ACCUM 0.25 ECH-A 1561.10 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 1523.2 ------------------------------------------------------------------------------------------------------------------------------------ 8 HD167756 HRS ACCUM 0.25 ECH-B 1807.93 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 1196.8 ------------------------------------------------------------------------------------------------------------------------------------ 9 HD167756 HRS ACCUM 0.25 ECH-B 2261.12 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 326.4 S ------------------------------------------------------------------------------------------------------------------------------------ 10 HD167756 HRS ACCUM 0.25 ECH-B 2603.71 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 217.6 S ------------------------------------------------------------------------------------------------------------------------------------ 11 HD167756 HRS ACCUM 0.25 ECH-B 2852.0 FP-SPLIT=DSFOUR,STEP-PATT=DEF 1 217.6 S ------------------------------------------------------------------------------------------------------------------------------------ 6575( 5) - 07/12/96 17:24 - [ 6] Summary Form for Proposal 6575 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT=DSFOUR STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category INTERSTELLAR MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 002 ONBOARD ACQ FOR 005-021 ONBOARD ACQ FOR 005-011 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N1 ECH-A ECH-B ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD119608 HD167756 ------------------------------------------------------------------------------------------------------------------------------------