6593( 6) - 08/09/96 14:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6593 Version: 6 Check-in Date: 09-Aug-1996 14:08:06 1.Proposal Title: ORIGIN AND PHYSICAL CONDITIONS IN THE LOCAL Ly-alpha FOREST ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle QSO ABSORPTION LINES GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. John Stocke UNIVERSITY OF COLORADO CoI: Dr. Michael Shull University of Colorado, Boulder N CoI: Mr. Steven Penton University of Colorado, Boulder N CoI: Dr. Ray Weymann Carnegie Observatories N CoI: Dr. Simon Morris Dominion Astrophysical Observatory N ------------------------------------------------------------------------------------ 6. Abstract We propose to use the GHRS+G160M grating to study the local Ly -alpha forest at high spectral resolution to better understand the origin and physical conditions of these clouds and their relationship (if any) to galaxies. Our targets are 7 very bright AGN with cz ~ 10,000 kms. Our program on Ly-alpha clouds differs in 3 important respects from the Absorption- Line Key Project and subsequent GHRS and FOS low- resolution projects: (1) It probes the very low column-density regime of Ly-alpha clouds, which may represent the low-redshift analogs of the very low metallicity high-redshift Ly-alpha clouds; (2) It is restricted to cz < 20,000 kms, allowing detailed ground- based studies of nearby galaxies with spectroscopy, H Alpha imaging, and 21 cm maps to very low luminosities; (3) It yields line profiles (Doppler widths, ionH1 columns, multiple components) at a resolution of ~15 kms (~10 times the FOS resolution) for cloud model discrimination. Our previous GHRS/G160M work showed that, unlike the high column density clouds, the low-N_H Ly-alpha clouds cluster only weakly with galaxies. However, there is no convincing case, among 24 GHRS clouds at cz < 20,000 kms examined thus far, for a cloud/galaxy association within 200 kpc. We detect 3--4 clouds in voids but our current statistics suggest that Ly-alpha clouds ``avoid the voids''. Our proposal will nearly double the number of high S/N Ly-alpha lines, double the number of nearby galaxy halos probed at D <= 750 kpc for weak Ly-alpha lines, and nearly double the pathlength through voids. ------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 2] Observations Description ------------------------ We propose to use the GHRS + G160M to obtain single spectra of 6 bright AGN with moderate redshift and sufficient flux >2 * 10^-14 ergs cm^-2 s^-1 Angstrom to obtain high-quality spectra in <= 10 orbits. The exposure times for these targets required to obtain S/N = 20 (4 Sigma limiting Ly-alpha equivalent width of 40 mAngstrom), range from 2--9 orbits for a total request of 32 orbits. The AGN targets have been chosen on the basis of mean fluxes from the Colorado IUE- AGN database of SWP spectra (Penton, Shull, & Edelson 1994) -- they are the brightest AGN with cz_em > 8000 kms in the sky. We winnowed the list of 10 such targets to the current 7 to maximize the pathlength, minimize the number of HST orbits, and to observe only those targets which STIS will not be more efficient in observing. Since STIS's primary advantage is a much broader wavelength coverage, we propose here only those targets for which the entire pathlength, or the remaining pathlength for Ly-alpha, can be observed with one GHRS/G160M setting. Three of our targets are in the high-efficiency ``continuous viewing zone''. For 5 targets, we will obtain one G160M exposure at ``setting 1'' (1222 --1258 Angstrom). The higher AGN redshifts of PKS 2155-304 and Fairall 9 allow us to push out farther in wavelength, with an additional 36 Angstrom setting. PKS 2155-304 and Fairall 9 already have scheduled or completed observations for our program in ``setting 1''. The target Mrk 279 (7 orbits) was chosen because of its extraordinary long pathlength available for Ly -alpha searches through a local void. In Cycles 2 and 4, we chose 4 targets behind voids defined by galaxy survey data, in strips limited in solid angle. For Cycle 6, we will relax the condition that the targets lie behind galaxy redshift survey areas and will conduct our own pencil-beam surveys around each sightline, as was done for 3C 273 (Morris et al. 1993). Real Time Justification ----------------------- None. We will conduct a 1degrees-radius pencil-beam survey of galaxy redshifts around each sightline, at Las Campanas for southern targets and at either CFHT or the WIYN telescope in the north. Each telescope has efficient multi-object spectroscopy capability to allow prompt sensitive surveys. We will also conduct sensitive 21 cm searches for ionH1 potentially associated with the Ly-alpha clouds using the VLA. Although we are aware that the 21 cm transition cannot detect the low column densities detected by our Ly-alpha survey, it is possible to detect higher column density material associated with tidal tails, low surface brightness galaxies, or intergalactic ionH1 clouds (as we have already done in some cases; Carilli et al. 1996). These very nearby systems are the only ones for which ionH1 21 cm emission mapping is feasible for detecting normal or dwarf galaxies; the FOS detected Ly-alpha lines are just too distant. Using Fabry-Perot or narrow-band filters, we can also search for H Alpha emission associated with incipient star formation in related low-surface brightness objects. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MARK817 Galaxy, Seyfert RA=14H 36M 22.068S +/- 0.1S, 2000 Z=0.033 V = 13.79+/-0.1 DEC=58D 47' 39.386" +/- 0.1", B-V = 0.40+/-0.1 PLATE-ID=01RR 2 ESO141-G55 Galaxy, Seyfert RA=19H 21M 14.287S +/- 0.1S, 2000 Z=0.037 V = 13.64+/-0.1 DEC=-58D 40' 14.869" +/- 0.1", B-V = 0.19+/-0.1 PLATE-ID=03D3 3 MARK279 Galaxy, Seyfert RA=13H 53M 03.447S +/- 0.1S, 2000 Z=0.031 V = 14.46+/-0.1 DEC=69D 18' 29.567" +/- 0.1", B-V = 0.69+/-0.1 PLATE-ID=0001 4 FAIRALL9 Galaxy, Quasar RA=01H 23M 45.705S +/- 0.1S, 2000 Z=0.047 V = 13.83+/-0.1 DEC=-58D 48' 21.580" +/- 0.1", B-V = 0.43+/-0.1 PLATE-ID=02IB 5 PKS2155-304 Galaxy, BL Lac RA=21H 58M 52.02S +/- 0.3S, DEC= J2000 Z=0.1165 V = 13.09+/-0.1 -30D 13' 32.300" +/- 3.0", PLATE B-V = 0.27+/-0.1 -ID=02J3 6 AKN120 Galaxy, Seyfert RA=05H 16M 11.421S +/- 0.1S, J2000 Z=0.033 V = 13.92+/-0.1 DEC=-00D 08' 59.377" +/- 0.1", B-V = 0.38+/-0.1 PLATE-ID=01O3 7 MARK509 Galaxy, Quasar RA=20H 44M 9.759S +/- 0.1S, DEC= 2000 Z=0.035 V = 13.12+/-0.1 -10D 43' 24.500" +/- 0.1", PLATE B-V = 0.23+/-0.1 -ID=00E1 6593( 6) - 08/09/96 14:16 - [ 5] Visit: 01 Visit Requirements: CVZ On Hold Comments: Additional Comments: MARK817-CVZ-5 ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 MARK817 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 11-13 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 11 MARK817 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 14 680 S STEP-PATT=5 Comments: SETTING#1, Part I, 14 x 680S, 31S unused ------------------------------------------------------------------------------------------------------------------------------------ 12 MARK817 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 13 680 S STEP-PATT=5 Comments: SETTING#1,Part II, 13 x 680S, 31s unused ------------------------------------------------------------------------------------------------------------------------------------ 13 MARK817 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 12 707.2 S STEP-PATT=5 Comments: SETTING#1,Part III, 12 x 707.2S ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 6] Visit: 02 Visit Requirements: CVZ On Hold Comments: Additional Comments: E141-G55_CVZ-3_ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 20 ESO141-G55 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 21-22 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 21 ESO141-G55 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 11 707.2 S STEP-PATT=5 Comments: SETTING#1, 3 CVZ orbits , complete , 39s unused ------------------------------------------------------------------------------------------------------------------------------------ 22 ESO141-G55 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 11 707.2 S STEP-PATT=5 Comments: SETTING#1, 3 CVZ orbits , complete , 39s unused ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 7] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: MARK279_7ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 30 MARK279 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 31-34 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 31 MARK279 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 9 680 S STEP-PATT=5 Comments: SETTING#1, 7 orbits, Part I, 9 x 680 S, 33S unused ------------------------------------------------------------------------------------------------------------------------------------ 32 MARK279 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 9 680 S STEP-PATT=5 Comments: SETTING#1, Part II, 9x680S, 33S unused ------------------------------------------------------------------------------------------------------------------------------------ 33 MARK279 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 9 680 S STEP-PATT=5 Comments: SETTING#1, Part III, 9x680S, 33S unused ------------------------------------------------------------------------------------------------------------------------------------ 34 MARK279 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 2 761.6 S STEP-PATT=5 Comments: SETTING#1, Part IV, 2 x 761.6, 33S unused ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 8] Visit: 04 Visit Requirements: CVZ On Hold Comments: Additional Comments: FAIRALL9_4_CVZ_ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 40 FAIRALL9 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 41-42 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 41 FAIRALL9 HRS ACCUM 2.0 G160M 1237.0 FP-SPLIT=NO,DOPPLER=ON, 23 625.6 S STEP-PATT=5 Comments: SETTING#0, 4 CVZ orbits, 23x23 (10.42m), 56s unused ------------------------------------------------------------------------------------------------------------------------------------ 42 FAIRALL9 HRS ACCUM 2.0 G160M 1257.5 FP-SPLIT=NO,DOPPLER=ON, 11 625.6 S STEP-PATT=5 Comments: SETTING#1.5, 4 CVZ orbits, 11x23 (10.42m), 56s unused ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 9] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: PKS2155-304_3_ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 50 PKS2155-304 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 51-52 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 51 PKS2155-304 HRS ACCUM 2.0 G160M 1276.0 FP-SPLIT=NO,DOPPLER=ON, 6 680 S STEP-PATT=5 Comments: SETTING#2, 3 orbits, Part I, 6 x 680 S, 24S unused ------------------------------------------------------------------------------------------------------------------------------------ 52 PKS2155-304 HRS ACCUM 2.0 G160M 1276.0 FP-SPLIT=NO,DOPPLER=ON, 5 680 S STEP-PATT=5 Comments: SETTING#2, 3 orbits, Part II, 5 x 680 S, 24S unused ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 10] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: AKN120_8ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 60 AKN120 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 61-64 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 61 AKN120 HRS ACCUM 2.0 G160M 1240.0 FP-SPLIT=NO,DOPPLER=ON, 9 680 S STEP-PATT=5 Comments: SETTING#1, Part I, 9*680, 8 orbits, 17s unused ------------------------------------------------------------------------------------------------------------------------------------ 62 AKN120 HRS ACCUM 2.0 G160M 1240.0 FP-SPLIT=NO,DOPPLER=ON, 9 680 S STEP-PATT=5 Comments: SETTING#1, Part II, 9x680, 8 orbits, 17s unused ------------------------------------------------------------------------------------------------------------------------------------ 63 AKN120 HRS ACCUM 2.0 G160M 1240 FP-SPLIT=NO,DOPPLER=ON, 9 680 S STEP-PATT=5 Comments: SETTING#1, Part III, 9*680S, 8 orbits ------------------------------------------------------------------------------------------------------------------------------------ 64 AKN120 HRS ACCUM 2.0 G160M 1240.0 FP-SPLIT=NO,DOPPLER=ON, 4 652.8 S STEP-PATT=5 Comments: SETTING#1, Part IV, 4*652.8, 8 orbits ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 11] Visit: 07 Visit Requirements: On Hold Comments: Additional Comments: MARK509_2ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 70 MARK509 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 13.5 S ONBOARD ACQuisition FOR 71 Comments: STEP-TIME=1.5S ------------------------------------------------------------------------------------------------------------------------------------ 71 MARK509 HRS ACCUM 2.0 G160M 1237.0 FP-SPLIT=NO,DOPPLER=ON, 7 652.8 S STEP-PATT=5 Comments: SETTING#0, 2 orbits, complete, 45 sec unused ------------------------------------------------------------------------------------------------------------------------------------ 6593( 6) - 08/09/96 14:16 - [ 12] Summary Form for Proposal 6593 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN STEP-PATT=5 DOPPLER=ON FP-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QSO ABSORPTION LINES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ ONBOARD ACQuisition FOR 11-13 ONBOARD ACQuisition FOR 21-22 ONBOARD ACQuisition FOR 31-34 ONBOARD ACQuisition FOR 41-42 ONBOARD ACQuisition FOR 51-52 ONBOARD ACQuisition FOR 61-64 ONBOARD ACQuisition FOR 71 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names MARK817 ESO141-G55 MARK279 FAIRALL9 PKS2155-304 AKN120 MARK509 ------------------------------------------------------------------------------------------------------------------------------------