6749( 9) - 12/13/96 10:39 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6749 Version: 9 Check-in Date: 13-Dec-1996 10:35:38 1.Proposal Title: A Study of the Gaseous Halo of the Andromeda Galaxy ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle GALAXIES & CLUSTERS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: LAURA DANLY POMONA COLLEGE CoI: Dr. J. Chris Blades Space Telescope Science Institute N CoI: Dr. David Bowen Space Telescope Science Institute N CoI: Dr. Elias Brinks NRAO N CoI: Prof. Colin Norman Johns Hopkins University N CoI: Prof. Rene Walterbos New Mexico State University N CoI: Paul Lee Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract We propose to study the gaseous environment of the Andromeda Galaxy (M31) by obtaining absorption line spectra of O I, Mg II, C II, Si II, C IV, and Si IV toward bright QSOs/AGN behind the galaxy. The lines of sight pass through a range of z- heights above the mid-plane (i.e. 3 - 16 kpc) and galactocentric distances (i.e. 20 - 40 kpc), permitting a study of different regions of this star forming galaxy. We will investigate the distribution, ionization, and kinematics of circum-galactic gas in M31 to gain insight into the physical mechanisms which govern its nature. We will compare results from M31 to the Milky Way, and will also use the data to provide information on the small scale structure on Milky Way halo gas. Learning about the physical mechanisms governing the origin and conditions in gas in the vicinity of galaxies provides a basis by which to interpret QSO absorption systems which are widely believed to originate in the vicinity of galaxies. An absorption line survey of the halo of our ``sister" spiral galaxy, Andromeda, has never before been conducted. The ultraviolet spectroscopic capability of HST provides the only means by which to accomplish this scientific goal. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose observing 2 QSOs with the G140L grating of the GHRS and 2 QSOs with both the G140L and G270M gratings. The G140L will cover the wavelength range at which Si IV, C IV, Si II, C II, and O I absorption will be expected from M31, while the G270M will cover the wavalengths at which Mg II absorption is expected. For all exposures, we will obtain WAVECALs to ensure the best accuracy. Exposure times are shown in Table 1, and are estimated either from known UV fluxes (Q00339+4005), or from V magnitudes extrapolated to 1400 Angstrom\\ and 2800 Angstrom\\ assuming the QSO flux follows a power law of the form F_Nu \\propto nu^-1. Exposure times are calculated to give a minimum S/N of 13 per pixel for half stepped data from the G140L grating, except for Q0034+3921 which is bright enought to give a S/N of 8 in a plausible exposure time. Exposure times were then adjusted to the nearest total exposure time corresponding to an integral number of orbits. Table 1 lists the 2Sigma equivalent width detection limit, assuming a background count rate of 36 counts diode^-1 hr^-1, and a resolving power of 2150 with the G140L at Si IV and R=2400 at C IV. These limits are smaller or comparable to the equivalent widths of absorption lines through our own Galactic halo, ~ 0.2 Angstrom , ~ 0.3 Angstrom . Exposure times are calculated to give a S/N of 5 per pixel for half stepped data from the G270M grating for Q0039+4005 & Q0039+4003. A S/N of 5 gives a 2Sigma equivalent width limit of 0.03 Angstrom\\ for a resolving power of 30,000 with the G270M. These limits will permit a search for the same low equivalent width absorption lines seen at higher redshift in QSO spectra. Real Time Justification ----------------------- None. Groundbased optical observations of the background targets will be obtained at the William Herschel Telescope on La Palma in October 1995. Data will be obtained on Ca II and Na I absorption in the vicinity of M31. However, the ground based optical data is not capable of providing information on atomic species arising in highly ionized gas. Further, while the optical data should provide information on the kinematics of any high column density material near M31, the Ca II and Na I lines are up to a thousand times less sensitive than the ultraviolet lines such as Mg II and C II. The optical lines are not suited to studying the low column density gas in the outskirts of M31; the sensitive UV lines are required. Results from our ground based program may affect our HST program in the following ways. If for some reason, one of our targets is found to be unsuitable as a background source (i.e. highly variable, low flux compared to literature values, etc.), we will adjust our observing program to maximize the scientific productivity. Second, if the Ca II observations are found to be unusually strong, suggesting possible saturation, we will adjust our program to observe a Mg II line that will not be saturated. Results from the ground based program will be in hand before the TAC meets; we will alert the TAC to any changes as needed. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Paul Lee*STSCI Ship Via: Email: plee@stsci.edu , ------------------------------------------------------------------------------------ 6749( 9) - 12/13/96 10:39 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 0039+4005 Galaxy, Seyfert, Radio RA=0H 41M 53.37S +/- 0.01S, J2000 Z=0.073 V = 15.14 Galaxy DEC=+40D 21' 17.5" +/- 0.1", B-V = 0.80 PLATE-ID=01JV Comments: EMISSION LINES CONTAMINATE B-V COLORS; CONTINUUM IS ASSUMED FLAT. 2 0039+4003 Galaxy, Seyfert RA=0H 42M 16.09S +/- 0.01S, J2000 Z=0.102 V = 16.3 DEC=+40D 19' 35.9" +/- 0.1", B-V = 0.75 PLATE-ID=01JV Comments: EMISSION LINES CONTAMINATE B-V COLORS; CONTINUUM IS ASSUMED FLAT. 3 0035+4112 Galaxy, Seyfert RA=0H 38M 33.12S +/- 0.01S, J2000 Z=0.073 V = 17.0 DEC=+41D 28' 50.3" +/- 0.1", PLATE-ID=01JV Comments: EMISSION LINES CONTAMINATE B-V COLORS; CONTINUUM IS ASSUMED FLAT. 4 0035+4112A Galaxy, Seyfert RA=0H 38M 33.12S +/- 0.01S, J2000 Z=0.073 V = 17.0 DEC=+41D 28' 50.3" +/- 0.1", PLATE-ID=01JV Comments: EMISSION LINES CONTAMINATE B-V COLORS; CONTINUUM IS ASSUMED FLAT. 6749( 9) - 12/13/96 10:39 - [ 2] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Early Target Acquisition Image for Visit 4 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 100 0035+4112 WFPC2 IMAGE WFALL F336W CR-SPLIT=DEF 1 1200 S ------------------------------------------------------------------------------------------------------------------------------------ 101 0035+4112 WFPC2 IMAGE WFALL F555W 1 30 S ------------------------------------------------------------------------------------------------------------------------------------ 102 0035+4112 WFPC2 IMAGE WFALL F555W CR-SPLIT=DEF 1 800 S ------------------------------------------------------------------------------------------------------------------------------------ 6749( 9) - 12/13/96 10:39 - [ 3] 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 ------------------------------------------------------------------------------------------------------------------------------------ 200 0039+4005 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 72 S ONBOARD ACQ FOR 250 - 287 Comments: STEP-TIME=4S ------------------------------------------------------------------------------------------------------------------------------------ 250 WAVE HRS ACCUM SC2 G270M 2798 1 DEF SEQ 250-260 NON-INT Comments: WAVELENGTH SETTING SHOULD INCLUDE 2796, 2802 ------------------------------------------------------------------------------------------------------------------------------------ 260 0039+4005 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 1 544 S CENSOR=YES Comments: EXPOSURE TIME 9.1M ------------------------------------------------------------------------------------------------------------------------------------ 261 0039+4005 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 6 544 S CENSOR=YES Comments: EXPOSURE TIME 54.4M ------------------------------------------------------------------------------------------------------------------------------------ 262 0039+4005 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 263 0039+4005 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 264 0039+4005 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 2 544 S CENSOR=YES Comments: EXPOSURE TIME 18.1M, TOTAL (260-264) 245M ------------------------------------------------------------------------------------------------------------------------------------ 270 WAVE HRS ACCUM SC2 G140L 1420 1 DEF SEQ 270-280 NON-INT Comments: WAVELENGTH SETTING SHOULD INCLUDE 1550A ------------------------------------------------------------------------------------------------------------------------------------ 280 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 1 544 S CENSOR=YES Comments: EXPOSURE TIME 9.1M ------------------------------------------------------------------------------------------------------------------------------------ 281 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 3 544 S CENSOR=YES Comments: EXPOSURE TIME 27.2M ------------------------------------------------------------------------------------------------------------------------------------ 282 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 283 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 6749( 9) - 12/13/96 10:39 - [ 4] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 284 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 285 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 6 544 S CENSOR=YES Comments: EXPOSURE TIME 54.4M ------------------------------------------------------------------------------------------------------------------------------------ 286 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 8 544 S CENSOR=YES Comments: EXPOSURE TIME 72.5M ------------------------------------------------------------------------------------------------------------------------------------ 287 0039+4005 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 1 54.4 S CENSOR=YES Comments: EXPOSURE TIME 54.4S, TOTAL (280-287) 409M ------------------------------------------------------------------------------------------------------------------------------------ 6749( 9) - 12/13/96 10:39 - [ 5] 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 ------------------------------------------------------------------------------------------------------------------------------------ 300 0039+4003 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 90 S ONBOARD ACQ FOR 350 - 383 Comments: STEP-TIME=10S ------------------------------------------------------------------------------------------------------------------------------------ 350 WAVE HRS ACCUM SC2 G270M 2798 1 DEF SEQ 350-360 NON-INT Comments: WAVELENGTH SETTING SHOULD INCLUDE 2796, 2802 ------------------------------------------------------------------------------------------------------------------------------------ 360 0039+4003 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 1 544 S CENSOR=YES Comments: EXPOSURE TIME 9.1M ------------------------------------------------------------------------------------------------------------------------------------ 361 0039+4003 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 5 544 S CENSOR=YES Comments: EXPOSURE TIME 45.3M ------------------------------------------------------------------------------------------------------------------------------------ 362 0039+4003 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 363 0039+4003 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 364 0039+4003 HRS ACCUM 2.0 G270M 2798 FP-SPLIT=NO,STEP-PATT=DEF, 2 652.8 S CENSOR=YES Comments: EXPOSURE TIME 19.9M, TOTAL (360-364) 238M ------------------------------------------------------------------------------------------------------------------------------------ 370 WAVE HRS ACCUM SC2 G140L 1420 1 DEF SEQ 370-380 NON-INT Comments: WAVELENGTH SETTING SHOULD INCLUDE 1550A ------------------------------------------------------------------------------------------------------------------------------------ 380 0039+4003 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 1 544 S CENSOR=YES Comments: EXPOSURE TIME 9.1M ------------------------------------------------------------------------------------------------------------------------------------ 381 0039+4003 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 3 544 S CENSOR=YES Comments: EXPOSURE TIME 27.2M ------------------------------------------------------------------------------------------------------------------------------------ 382 0039+4003 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 383 0039+4003 HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 6 544 S CENSOR=YES Comments: EXPOSURE TIME 54.4M, TOTAL (380-382) 172.3M ------------------------------------------------------------------------------------------------------------------------------------ 6749( 9) - 12/13/96 10:39 - [ 6] Visit: 04 Visit Requirements: ON HOLD FOR 1 On Hold Comments: Waiting for Early Acquisition data from visit 1 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 ------------------------------------------------------------------------------------------------------------------------------------ 400 0035+4112A HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 114.75 ONBOARD ACQ FOR 450 - 465 Comments: STEP-TIME=12.75S ------------------------------------------------------------------------------------------------------------------------------------ 450 WAVE HRS ACCUM SC2 G140L 1420 1 DEF SEQ 450-460 NON-INT Comments: WAVELENGTH SETTING SHOULD INCLUDE 1550A ------------------------------------------------------------------------------------------------------------------------------------ 460 0035+4112A HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 1 544 S CENSOR=YES Comments: EXPOSURE TIME 9.1M ------------------------------------------------------------------------------------------------------------------------------------ 461 0035+4112A HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 3 544 S CENSOR=YES Comments: EXPOSURE TIME 27.2M ------------------------------------------------------------------------------------------------------------------------------------ 462 0035+4112A HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 463 0035+4112A HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 464 0035+4112A HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 9 544 S CENSOR=YES Comments: EXPOSURE TIME 81.6M ------------------------------------------------------------------------------------------------------------------------------------ 465 0035+4112A HRS ACCUM 2.0 G140L 1420 FP-SPLIT=NO,STEP-PATT=DEF, 3 652.8 S CENSOR=YES Comments: EXPOSURE TIME 29.2M, TOTAL (460-465) 281.1M ------------------------------------------------------------------------------------------------------------------------------------ 6749( 9) - 12/13/96 10:39 - [ 7] Summary Form for Proposal 6749 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=DEF BRIGHT=RETURN CENSOR=YES STEP-PATT=DEF FP-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 250 - 287 SEQ 250-260 NON-INT SEQ 270-280 NON-INT ONBOARD ACQ FOR 350 - 383 SEQ 350-360 NON-INT SEQ 370-380 NON-INT ON HOLD FOR 1 ONBOARD ACQ FOR 450 - 465 SEQ 450-460 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F555W MIRROR-N2 G270M G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names 0035+4112 0039+4005 WAVE 0039+4003 0035+4112A ------------------------------------------------------------------------------------------------------------------------------------