6164( 7) - 11/22/95 16:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6164 Version: 7 Check-in Date: ********** 1.Proposal Title: Composition of Gas in Individual Interstellar Clouds: Cycle 5 DDT Observations ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO/DD 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Lyman Spitzer Princeton University Observatory CoI: Edward L. Fitzpatrick Princeton University Observatory Y ------------------------------------------------------------------------------------ 6. Abstract In this Cycle 5 DDT program, spectroscopic observations of interstellar absorption lines will be made towards 2 stars in the Galactic disk using the Goddard High Resolution Spectrograph in its highest resolution modes. The star HD160578 will be observed with both the Ech-A and Ech-B modes. The star HD202904 will be observed only with the Ech-A; these data will be combined with Ech-B observations to be obtained for this star with a Cycle 5 GTO program. All these data will be analyzed to determine column densities in individual interstellar clouds for approximately 19 species from 11 different elements. These measurements will determine how the composition of the gas in such clouds and the various physical processes occurring vary with cloud parameters such as H column density, velocity, ionization level, and distance z from the galactic plane. This information should help to clarify the many physical processes occurring in interstellar gas. ------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 2] Observations Description ------------------------ Much pioneering work on the study of individual interstellar clouds has been done from the ground. However, to obtain data on many elements, including the highly-ionized species, requires observations from above the atmosphere. The Copernicus satellite made important contributions to this topic, but its resolving power of 20,000 was insufficient to resolve clearly many of the individual components in most lines of sight; although in favorable cases properties of individual clouds were successfully deduced. The IUE satellite has been enormously useful for broad surveys of interstellar absorption, especially for the fainter stars which could not be observed with Copernicus, but its resolving power of 10,000 is inadequate for resolving most components. The HST, with its resolving power of 85,000 for lines observed with Echelle A and Echelle B, can answer detailed questions on the physical properties of individual clouds towards many stars. Two stars in the Galactic disk, HD160578 and HD202904, will be observed under this Cycle 5 DDT program. The observations will follow the pattern set in previous cycles. In general, we require for each star observations of a series of interstellar lines -- using the Echelle A for lines shortward of 1800 A and the Echelle B for lines longward of 1800 A. The use of the echelles and the Small Science Aperture (SSA) will yield the highest resolution available with the GHRS (resolving power R about 85,000). For photometric accuracy, the FP-SPLIT mode is used to give four adjacent exposures of each line. Lines from 19 different species, corresponding to 11 different elements, are included in the observations, namely, C I, C II, C IV, N V, O I, Mg I, Mg II, S I, S II, S III, Si II, Si III, Si IV, P II, P III, Mn II, Cr II, Fe II, and Zn II. Since Echelle B observations for HD202904 will be acquired in a separate Cycle 5 GTO program, for this star we will obtain only Echelle A data under this DDT program. The scientific goal of the program is to determine column densities in individual interstellar clouds for each of the many species included in the observations. These measurements will determine how the composition of the gas in such clouds and the various physical processes occurring vary with cloud parameters such as H column density, velocity, ionization level, and distance z from the galactic plane. This information should help to clarify the many physical processes occurring in interstellar gas. The program should also increase our understanding of the balance between formation and destruction of interstellar dust grains. Real Time Justification ----------------------- There are no special requirements. Calibration Justification ------------------------- There are no coordinated and/or supporting observations. Additional Comments ------------------- There are no additional comments. ------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 25 HD160578 STAR, B0-B2 III-I RA = 17H 42M 29.28S +/- 0.01S, J2000 F-CONT(1300) = 1.7 +/- 0.2 E-8 DEC = -39D 01' 48.1" +/- 0.1" V = 2.41 +/- 0.05 B-V = -0.22 TYPE = B1.5 III Comments: Coordinates are from Hipparcos INCA Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.000 0.0 0.0 0.0 27 HD202904 STAR, BE RA = 21H 17M 55.06S +/- 0.01S, J2000 F-CONT(1300) = 5.0 +/- 0.2 E-10 DEC = 34D 53' 48.5" +/- 0.1" V = 4.43 +/- 0.05 B-V = -0.11 TYPE = B2 Ve Comments: Coordinates are from Hipparcos INCA Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.000 0.0 0.0 0.0 6164( 7) - 11/22/95 16:58 - [ 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 HD160578 HRS ACQ 2.0 MIRROR-A1 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 2 HD160578 HRS ACQ/PEA 0.25 MIRROR-A1 1 5S ONBOARD ACQ FOR 3 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 3 HD160578 HRS ACQ/PEA 0.25 MIRROR-A1 1 5S ONBOARD ACQ FOR 4-12 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 4 HD160578 HRS ACCUM 0.25 ECH-A 1192.53 FP- 1 326.4S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 5 HD160578 HRS ACCUM 0.25 ECH-A 1241.00 FP- 1 217.6S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 6 HD160578 HRS ACCUM 0.25 ECH-A 1252.89 FP- 1 163.2S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 7 HD160578 HRS ACCUM 0.25 ECH-A 1262.22 FP- 1 217.6S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 8 HD160578 HRS ACCUM 0.25 ECH-A 1303.47 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 9 HD160578 HRS ACCUM 0.25 ECH-A 1335.32 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 10 HD160578 HRS ACCUM 0.25 ECH-A 1393.97 FP- 1 163.2S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 HD160578 HRS ACCUM 0.25 ECH-A 1549.71 FP- 1 326.4S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 12 HD160578 HRS ACCUM 0.25 ECH-A 1561.10 FP- 1 326.4S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 7] 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 HD160578 HRS ACQ 2.0 MIRROR-A1 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 2 HD160578 HRS ACQ/PEA 0.25 MIRROR-A1 1 5S ONBOARD ACQ FOR 3 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 3 HD160578 HRS ACQ/PEA 0.25 MIRROR-A1 1 5S ONBOARD ACQ FOR 4-12 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 4 HD160578 HRS ACCUM 0.25 ECH-A 1355.80 FP- 1 326.4S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 5 HD160578 HRS ACCUM 0.25 ECH-B 1807.93 FP- 1 380.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 6 HD160578 HRS ACCUM 0.25 ECH-B 2027.00 FP- 1 217.6S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 7 HD160578 HRS ACCUM 0.25 ECH-B 2059.77 FP- 1 217.6S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 8 HD160578 HRS ACCUM 0.25 ECH-B 2261.12 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 9 HD160578 HRS ACCUM 0.25 ECH-B 2371.36 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 10 HD160578 HRS ACCUM 0.25 ECH-B 2603.71 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 HD160578 HRS ACCUM 0.25 ECH-B 2800.36 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 12 HD160578 HRS ACCUM 0.25 ECH-B 2853.39 FP- 1 108.8S SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 9] 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD202904 HRS ACQ 2.0 MIRROR-N1 1 1.8S ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 2 HD202904 HRS ACQ/PEA 0.25 MIRROR-N1 1 5S ONBOARD ACQ FOR 3-11 KUP Comments: STEP-TIME = 0.2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 3 HD202904 HRS ACCUM 0.25 ECH-A 1192.53 FP- 1 1523.2S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 4 HD202904 HRS ACCUM 0.25 ECH-A 1241.00 FP- 1 870.4S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 5 HD202904 HRS ACCUM 0.25 ECH-A 1252.89 FP- 1 652.8S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 6 HD202904 HRS ACCUM 0.25 ECH-A 1262.22 FP- 1 870.4S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 7 HD202904 HRS ACCUM 0.25 ECH-A 1303.47 FP- 1 544S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 8 HD202904 HRS ACCUM 0.25 ECH-A 1335.32 FP- 1 544S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 9 HD202904 HRS ACCUM 0.25 ECH-A 1393.97 FP- 1 544S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 10 HD202904 HRS ACCUM 0.25 ECH-A 1549.71 FP- 1 979.2S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 11 HD202904 HRS ACCUM 0.25 ECH-A 1561.10 FP- 1 870.4S SPLIT=DSFOUR, STEP-PATT=DEF ------------------------------------------------------------------------------------------------------------------------------------ 6164( 7) - 11/22/95 16:58 - [ 10] Summary Form for Proposal 6164 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT=DSFOUR STEP-PATT=DEF COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO/DD ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2 ONBOARD ACQ FOR 3 ONBOARD ACQ FOR 4-12 ONBOARD ACQ FOR 3-11 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-A1 ECH-A ECH-B MIRROR-N1 ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD160578 HD202904 ------------------------------------------------------------------------------------------------------------------------------------