5883( 0) - 07/18/95 18:26 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5883 Version: ********** Check-in Date: ********** 1.Proposal Title: Properties of the High-Velocity Cloud Towards HD 203664 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Francis Keenan The Queen's University of Belfast CoI: Philip Dufton The Queen's University of Belfast N CoI: Kenneth Sembach Massachusetts Institute of Technology Y ------------------------------------------------------------------------------------ 6. Abstract We will obtain high- and intermediate-resolution GHRS spectra of the +70 km/sec HVC seen toward HD 203664 in optical and radio spectra. The observations will provide a unique opportunity to quantify the ionization structure of a HVC and accurately determine the chemical abundances of important elements such as C, N, O, Mg, Si, S, Cr, Mn, Fe, and Zn in high velocity interstellar material. Our high spectral resolution optical data suggest that substructure may exist within the HVC which, if confirmed, would support the possibility that early-type stars at large distances from the Galactic plane are formed through star formation induced by collisions between cloudlets within HVCs. We will test this hypothesis on the HD 203664 HVC with high S/N absorption line measurements made by the GHRS in its highest resolution mode. By combining a supporting set of optical and radio data with the ultraviolet observations, we will study the velocity structure of the HVC, morphology, distance, and physical conditions of this HVC in greater detail than has been possible for any other high velocity cloud in the sky. ------------------------------------------------------------------------------------ 5883( 0) - 07/18/95 18:26 - [ 2] Observations Description ------------------------ We will obtain spectroscopic observations of the HVC absorption toward HD 203664 using both the highest resolution (echelle) and intermediate resolution gratings of the GHRS. The light of HD 203664 will be placed in the large science aperture (LSA). The data will be obtained with the default diode substepping (step-patterns 5 and 7). Comb-addition and the FP-SPLIT=4 procedures will be used to reduce fixed pattern noise in the data. All exposures will be broken into shorter exposures (either through the use of FP- SPLIT or through explicit breaks) to ensure that geomagnetically-induced image blurring of the data is minimized. Resolution and sensitivity estimates were taken from the post-COSTAR GHRS instrument handbook (Version 5.0, May 1994). Flux estimates for each observation were determined from our recent IUE echelle spectra and should be accurate to ~15%. Exposure calculations include an allowance for background determinations with the full diode array as part of the substepping procedures. The expected S/N values of ~50-70 are appropriate for a (Nyquist) sampling of 2 substeps/diode, but we will obtain 4 samples per diode and rebin the data without loss of resolution after acquisition. Real Time Justification ----------------------- No special scheduling requirements are necessary. Calibration Justification ------------------------- No special scheduling requirements are necessary. Additional Comments ------------------- No additional comments at this time. ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Kenneth Sembach*Center for Space Research*MIT 6-216*77 Massachusetts Avenue*Cambridge, MA 02139 Ship Via: UPS Email: sembach@sundoggie.mit.edu , ------------------------------------------------------------------------------------ 5883( 0) - 07/18/95 18:26 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD203664 STAR, B0-B2 V-IV RA=21H 23M 28.84S +/- 0.02S, J2000 V = +110 V = 8.42 +/- 0.40 DEC=+09D 55' 54.7" +/- 0.3" B-V = -0.19 +/- 0.10 F-CONT(1240) = 4.0 +/- 0.2 E-11 F-CONT(1550) = 0.8 +/- 0.2 E-11 F-CONT(2600) = 1.1 +/- 0.2 E-11 Comments: Hipparcos coords and proper motions. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.000 0.0003 -0.014 0.0 5883( 0) - 07/18/95 18:26 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: First visit to obtain Side 1 spectra (4 orbits). Number exposures beginning with 10. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD203664 HRS ACQ 2.0 MIRROR-N1 BRIGHT=RETURN, 1 1.8S ONBOARD ACQ FOR 20-70 SEARCH-SIZE=3 Comments: Expect about 74,000 cnt/s using mirror N1. STEP-TIME = 0.2 seconds. Ok as long as BRIGHT=RETURN is used. ------------------------------------------------------------------------------------------------------------------------------------ 20 HD203664 HRS ACCUM 2.0 ECH-A 1335.1 FP-SPLIT=FOUR, 1 1523.2S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = C II, C II* ------------------------------------------------------------------------------------------------------------------------------------ 30 HD203664 HRS ACCUM 2.0 ECH-A 1303.4 FP-SPLIT=FOUR, 1 1305.6S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = O I, O I*, Si II, S I ------------------------------------------------------------------------------------------------------------------------------------ 40 HD203664 HRS ACCUM 2.0 G140M 1396.5 FP-SPLIT=FOUR, 1 1196.8S COMB=FOUR, STEP -PATT=5, DOPPLER=ON Comments: Lines = Si IV, Ni II ------------------------------------------------------------------------------------------------------------------------------------ 50 HD203664 HRS ACCUM 2.0 G140M 1248.3 FP-SPLIT=FOUR, 1 761.6S COMB=FOUR, STEP -PATT=5, DOPPLER=ON Comments: Lines = Ge II, N V, Mg II, S I, S II, Si II ------------------------------------------------------------------------------------------------------------------------------------ 60 HD203664 HRS ACCUM 2.0 G140M 1544.5 FP-SPLIT=FOUR, 2 1523.2S COMB=FOUR, STEP -PATT=5, DOPPLER=ON Comments: Lines = P II, C IV ------------------------------------------------------------------------------------------------------------------------------------ 70 HD203664 HRS ACCUM 2.0 G140M 1199.0 FP-SPLIT=FOUR, 1 1305.6S COMB=FOUR, STEP -PATT=5, DOPPLER=ON Comments: Lines = S III, Si II, Si III, Mn II, N I ------------------------------------------------------------------------------------------------------------------------------------ 5883( 0) - 07/18/95 18:26 - [ 5] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Second visit to obtain Side 2 spectra (5 orbits). Number exposures beginning with 110. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 110 HD203664 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN, 1 1.8S ONBOARD ACQ FOR 120-210 SEARCH-SIZE=3 Comments: Expect about 400,000 cnt/s using mirror N2. STEP-TIME = 0.2 seconds. Ok as long as BRIGHT=RETURN is used. ------------------------------------------------------------------------------------------------------------------------------------ 120 HD203664 HRS ACCUM 2.0 ECH-B 2061.62 FP-SPLIT=FOUR, 2 761.6S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Cr II, Zn II ------------------------------------------------------------------------------------------------------------------------------------ 130 HD203664 HRS ACCUM 2.0 ECH-B 1807.6 FP-SPLIT=FOUR, 2 979.2S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Si II, S I, Ni II ------------------------------------------------------------------------------------------------------------------------------------ 140 HD203664 HRS ACCUM 2.0 ECH-B 2371.3 FP-SPLIT=FOUR, 1 761.6S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Fe II ------------------------------------------------------------------------------------------------------------------------------------ 150 HD203664 HRS ACCUM 2.0 ECH-B 2603.3 FP-SPLIT=FOUR, 1 1088S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Fe II, Mn II ------------------------------------------------------------------------------------------------------------------------------------ 160 HD203664 HRS ACCUM 2.0 ECH-B 2851.9 FP-SPLIT=FOUR, 1 979.2S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Mg I ------------------------------------------------------------------------------------------------------------------------------------ 170 HD203664 HRS ACCUM 2.0 ECH-B 2800.0 FP-SPLIT=FOUR, 1 761.6S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Mg II ------------------------------------------------------------------------------------------------------------------------------------ 5883( 0) - 07/18/95 18:26 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 180 HD203664 HRS ACCUM 2.0 ECH-B 2260.8 FP-SPLIT=FOUR, 1 1305.6S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Fe II ------------------------------------------------------------------------------------------------------------------------------------ 190 HD203664 HRS ACCUM 2.0 ECH-B 2026.2 FP-SPLIT=FOUR, 1 1414.4S COMB=FOUR, STEP -PATT=7, DOPPLER=ON Comments: Lines = Zn II, Mg I ------------------------------------------------------------------------------------------------------------------------------------ 200 HD203664 HRS ACCUM 2.0 G160M 1856.5 FP-SPLIT=FOUR, 1 979.2S COMB=FOUR, STEP -PATT=5, DOPPLER=ON Comments: Lines = Al III ------------------------------------------------------------------------------------------------------------------------------------ 210 HD203664 HRS ACCUM 2.0 G160M 1670.8 FP-SPLIT=FOUR, 1 652.8S COMB=FOUR, STEP -PATT=5, DOPPLER=ON Comments: Lines = Al II ------------------------------------------------------------------------------------------------------------------------------------ 5883( 0) - 07/18/95 18:26 - [ 7] Summary Form for Proposal 5883 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=3 DOPPLER=ON STEP-PATT=7 STEP-PATT=5 COMB=FOUR FP-SPLIT=FOUR ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 20-70 ONBOARD ACQ FOR 120-210 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N1 ECH-A G140M MIRROR-N2 ECH-B G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD203664 ------------------------------------------------------------------------------------------------------------------------------------