! Proposal 6178, submission 4 ! PI: C.R. O'Dell ! Received Fri Aug 25 15:33:12 EDT 1995 ! From: fitz@astro.Princeton.EDU ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal ! C.R. O'Dell, P.I. & Lyman Spitzer, Co.I. ! Continuation of GTO Program 1071 ! Proposal_Information Title: Composition of Gas in Individual Interstellar Clouds: Cycle 5 GTO Observations Proposal_Category: GTO/OS Scientific_Category: Interstellar Medium Cycle: 5 Investigators PI_name: C.R. O'Dell PI_Institution: Rice University CoI_name: Lyman Spitzer CoI_Institution: Princeton University Observatory CoI_name: Edward L. Fitzpatrick CoI_Institution: Princeton University Observatory Contact: Y Abstract: In this Cycle 5 GTO program, spectroscopic observations of interstellar absorption lines will be made towards 1 star in the Galactic halo and 2 stars in the Galactic disk using the Goddard High Resolution Spectrograph in its highest resolution modes. The halo star HD149881 and the disk star HD36486 will be observed with the Ech-A; these data will be combined with Ech-B data obtained for these stars in previous observing cycles. The disk star HD202904 will be observed with the Ech-B; these data will be combined with Ech-A observations for this star to be obtained with a Cycle 5 DDT program. 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. Questions Observing_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. Three stars, HD149881 (in the Galactic halo), HD36486 (in the disk) and HD202904 (in the disk), will be observed under this Cycle 5 GTO 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 have been acquired already for HD149881 and HD36486 in previous observing cycles, for these two stars we will obtain only Echelle A exposures under this Cycle 5 program. For HD202904, only the Echelle B exposures will be obtained under this GTO program; Echelle A data for this star will be obtained in a separate Cycle 5 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. In particular, these measurements for the galactic halo star HD 149881, together with those for three halo stars observed in earlier cycles, should help to identify the mechanisms responsible for the abundant C IV, Si IV, and N V known to be present in the interstellar gas at kiloparsec distances from the galactic plane. 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. ! ! ***** TARGET LIST FOLLOWS ****** ! Fixed_Targets ! Target data updated 7/18/95 - AFB Target_Number: 2 Target_Name: HD149881 Alternate_Names: GSC0973-00729 Description: STAR, B0-B2 III-I Position: RA = 16H 36M 58.18S +/- 0.01S, DEC = 14D 28' 30.6" +/- 0.1" Equinox: J2000 Epoch: 2000.000 Flux: F-CONT(1300) = 2.9 +/- 0.6 E-10, V = 7.03 +/- 0.05, B-V = -0.19, TYPE = B0.5 II Comments: Coordinates are from Hipparcos INCA Target_Number: 11 Target_Name: HD36486 Alternate_Names: DELTA-ORIONIS, GSC4766-02445 Description: STAR, SUPERGIANT O Position: RA = 5H 32M 0.36S +/- 0.01S, DEC = -00D 17' 56.7" +/- 0.1" Equinox: J2000 Epoch: 2000.000 Flux: F-CONT(1300) = 2.2 +/- 0.2 E-8, V = 2.23 +/- 0.05, B-V = -0.23, TYPE = O9.5 II Comments: Coordinates are from Hipparcos INCA Target_Number: 27 Target_Name: HD202904 Alternate_Names: UPSILON-CYGNI, GSC2710-02647 Description: STAR, BE Position: RA = 21H 17M 55.06S +/- 0.01S, DEC = 34D 53' 48.5" +/- 0.1" Equinox: J2000 Epoch: 2000.000 Flux: F-CONT(1300) = 5.0 +/- 0.2 E-10, V = 4.43 +/- 0.05, B-V = -0.11, TYPE = B2 Ve Comments: Coordinates are from Hipparcos INCA ! ! ***** VISIT/EXPOSURE LOGSHEET FOLLOWS ***** ! Visits Visit_Number: 1 Exposure_Number: 1 Target_Name: HD36486 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 2 Target_Name: HD36486 Config: HRS Opmode: ACQ/PEAKUP Aperture: 0.25 Sp_Element: MIRROR-A1 Time_Per_Exposure: 5.0S Special_Requirements: ONBOARD ACQ FOR 3 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 3 Target_Name: HD36486 Config: HRS Opmode: ACQ/PEAKUP Aperture: 0.25 Sp_Element: MIRROR-A1 Time_Per_Exposure: 5.0S Special_Requirements: ONBOARD ACQ FOR 4-12 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 4 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1192.53 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 217.60S Exposure_Number: 5 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1241.00 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 163.2S Exposure_Number: 6 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1252.89 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 108.8S Exposure_Number: 7 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1262.22 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 108.8S Exposure_Number: 8 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1303.47 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 108.8S Exposure_Number: 9 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1335.32 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 108.8S Exposure_Number: 10 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1393.97 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 272.0S Exposure_Number: 11 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1549.71 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 435.2S Exposure_Number: 12 Target_Name: HD36486 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1561.10 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF, COMB=TWO Number_of_Iterations: 1 Time_Per_Exposure: 272.0S Visit_Number: 2 Exposure_Number: 1 Target_Name: HD149881 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 2 Target_Name: HD149881 Config: HRS Opmode: ACQ/PEAKUP Aperture: 0.25 Sp_Element: MIRROR-N1 Time_Per_Exposure: 5.0S Special_Requirements: ONBOARD ACQ FOR 3-11 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 3 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1192.53 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 2 Time_Per_Exposure: 1088.0S Exposure_Number: 4 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1241.00 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1523.2S Exposure_Number: 5 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1252.89 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1523.2S Exposure_Number: 6 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1262.22 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1305.6S Exposure_Number: 7 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1303.47 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 979.2S Exposure_Number: 8 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1335.32 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1523.2S Exposure_Number: 9 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1393.97 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1632.0S Exposure_Number: 10 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1549.71 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 2 Time_Per_Exposure: 1196.8S Exposure_Number: 11 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1561.10 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 2 Time_Per_Exposure: 1632.0S Visit_Number: 3 Exposure_Number: 1 Target_Name: HD202904 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A2 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 2 Target_Name: HD202904 Config: HRS Opmode: ACQ/PEAKUP Aperture: 0.25 Sp_Element: MIRROR-A2 Time_Per_Exposure: 5.0S Special_Requirements: ONBOARD ACQ FOR 3-8 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 3 Target_Name: HD202904 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-B Wavelength: 1807.93 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 761.6S Exposure_Number: 4 Target_Name: HD202904 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-B Wavelength: 2027.00 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 326.4S Exposure_Number: 5 Target_Name: HD202904 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-B Wavelength: 2059.77 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 435.2S Exposure_Number: 6 Target_Name: HD202904 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-B Wavelength: 2261.12 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 217.6S Exposure_Number: 7 Target_Name: HD202904 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-B Wavelength: 2371.36 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 217.6S Exposure_Number: 8 Target_Name: HD202904 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-B Wavelength: 2603.71 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 217.6S Visit_Number: 4 Exposure_Number: 1 Target_Name: HD149881 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 2 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 2 Target_Name: HD149881 Config: HRS Opmode: ACQ/PEAKUP Aperture: 0.25 Sp_Element: MIRROR-N1 Time_Per_Exposure: 5.0S Special_Requirements: ONBOARD ACQ FOR 3-11 Comments: STEP-TIME = 0.2 SEC Exposure_Number: 3 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1192.53 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 2 Time_Per_Exposure: 1088.0S Exposure_Number: 4 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1241.00 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1523.2S Exposure_Number: 5 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1252.89 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1523.2S Exposure_Number: 6 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1262.22 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1305.6S Exposure_Number: 7 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1303.47 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 979.2S Exposure_Number: 8 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1335.32 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1523.2S Exposure_Number: 9 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1393.97 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 1 Time_Per_Exposure: 1632.0S Exposure_Number: 10 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1549.71 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 2 Time_Per_Exposure: 1196.8S Exposure_Number: 11 Target_Name: HD149881 Config: HRS Opmode: ACCUM Aperture: 0.25 Sp_Element: ECH-A Wavelength: 1561.10 Optional_Parameters: FP-SPLIT=DSFOUR, STEP-PATT=DEF Number_of_Iterations: 2 Time_Per_Exposure: 1632.0S ! ! ***** DATA DISTRIBUTION FOLLOWS ***** ! Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: Lyman Spitzer, Jr. Princeton University Observatory Peyton Hall, Ivy Lane Princeton, NJ 08544 ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: fitz@astro.princeton.edu