9378( 2) - 02/18/02 10:41 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9378 Version: 2 Check-in Date: 18-Feb-2002 10:40:29 1.Proposal Title: Galaxy Dynamics at Very Large Radius using LyAlpha Absorption Lines ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Stephanie Cote Dominion Astrophysical Observatory CoI: Dr. Sebastien Blais-Ouellette Universite de Montreal N CoI: Dr. Tom Broadhurst Hebrew University N CoI: Prof. Claude Carignan Universite de Montreal N CoI: Prof. Ken Freeman Mount Stromlo Observatory N CoI: Prof. Rosemary Wyse The Johns Hopkins University N ------------------------------------------------------------------------------------ 5. Abstract We propose to investigate the outer dynamics of the nearby spiral galaxy NGC1398 at very large galactocentric radii by using the kinematical information from Ly-alpha absorption lines in the spectra of 3 background UV-bright objects (two Seyferts 1 and one QSO). It is a unique opportunity to have 3 UV-bright objects surrounding one single isolated spiral galaxy, and this will enable us to measure its disk rotation up to radii several times greater than what is possible in HI at 21cm, since the UV- bright objects lie at projected distances of ~ 80 to 270 kpc. At these large radii we expect to observe the turn down from flat rotation, and be able to determine the size of the dark matter halo and hence measure the total mass and mass-to-light ratio of a spiral galaxy. ------------------------------------------------------------------------------------ 9378( 2) - 02/18/02 10:41 - [ 2] Observations Description ------------------------ We want to target two Sy1 (MS0337.1-2645 and MS0335.4-2618) and one QSO (HE0340 -2703) with STIS with the G140M grating to detect an absorption feature in a range from ~eq 1220 Angstrom to 1222.6 Angstrom , with a velocity precision of at least 1/3 of the resolution (~eq 10 kms ). The small aperture width of 0.1" will be preferred, so as to avoid degrading the spectral purity. None of our objects have previously measured fluxes at 1220 Angstrom , so the integration times were estimated using a template QSO spectrum, redshifted to respectively z=0.11, 0.123 and 0.283 for MS0337.1-2645, MS0335.4-2618, and HE0340-2703. Our three objects have respectively V=15.5, 16.5 and 16.85 (Puchnarewicz et al 1992 -note that the magnitudes were calculated from optical long-slit spectra so should be representative of the Seyfert nuclei; Stocke et al 1991, Reimers et al 1996). This gives peak local count rates of 2 * 10^-2, 1.8 * 10^-2 and 1.7 * 10^-2 counts s^-1 pixel^-1 at the Geocoronal Lyalpha (1215.6A). These are orders of magnitude away from the MAMA Bright Objects limits. We need a S/N ~eq 5 with the G140M to detect lines with the required equivalent widths W > 0.1 Angstrom. Hence the exposure times needed are 16, 37 and 67 minutes. The guide star and target acquisitions will each require 6 minutes, followed by the acquisition peakups with the narrow slit needing another ~6 minutes (using the normal F28X50LP filter). The visibility period for our objects is about 53 minutes. Counting with all the overheads, we need 1, 2, and 2 orbits respectively, for a total of 5 orbits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9378( 2) - 02/18/02 10:41 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MS0337.1- GALAXY, SEYFERT RA=03H 39M 13.52S +/- 0.05S, J2000.0 Z=0.11 V = 15.5 2645 DEC=-26D 36' 49.3" +/- 0.3", E(B-V) = 0.013 PLATE-ID=027X F(1220)=1.1+/-1e-15 Coordinate Source: GSC_SURVEY_PLATE 2 MS0335.4- GALAXY, SEYFERT RA=03H 37M 33.87S +/- 0.05S, J2000.0 Z=0.123 V = 16.5 2618 DEC=-26D 09' 22.3" +/- 0.3", E(B-V) = 0.013 PLATE-ID=027X F(1220)=4.3+/-4e-16 Coordinate Source: GSC_SURVEY_PLATE 3 HE0340-2703 GALAXY, QSO RA=03H 42M 20.50S +/- 0.05S, J2000.0 Z=0.283 V = 16.85 DEC=-26D 53' 59.2" +/- 0.3", E(B-V) = 0.01 PLATE-ID=027X F(1220)=2.5+/-2.5e-16 Coordinate Source: GSC_SURVEY_PLATE 9378( 2) - 02/18/02 10:41 - [ 4] Visit: 01 Visit Priority: 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 ------------------------------------------------------------------------------------------------------------------------------------ 101 MS0337.1-26 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 3.0 S 45 CD P ------------------------------------------------------------------------------------------------------------------------------------ 102 MS0337.1-26 STIS/C ACQ/PEA 52X0.1 MIRROR 1 6.0 S 45 CD K ------------------------------------------------------------------------------------------------------------------------------------ 103 MS0337.1-26 STIS/F ACCUM 52X0.1 G140M 1222 1 30 M EXPAND 45 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9378( 2) - 02/18/02 10:41 - [ 5] Visit: 02 Visit Priority: 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 ------------------------------------------------------------------------------------------------------------------------------------ 201 MS0335.4-26 STIS/C ACQ F28X50L MIRROR ACQTYPE=DIFFUSE , 1 6.0 S 18 CD P DIFFUSE-CENTER=FLUX-CENTROID , CHECKBOX=9 ------------------------------------------------------------------------------------------------------------------------------------ 202 MS0335.4-26 STIS/C ACQ/PEA 52X0.1 MIRROR 1 15.0 S 18 CD K ------------------------------------------------------------------------------------------------------------------------------------ 203 MS0335.4-26 STIS/F ACCUM 52X0.1 G140M 1222 1 30 M EXPAND 18 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 204 MS0335.4-26 STIS/F ACCUM 52X0.1 G140M 1222 1 45 M EXPAND 18 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9378( 2) - 02/18/02 10:41 - [ 6] Visit: 03 Visit Priority: 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 ------------------------------------------------------------------------------------------------------------------------------------ 301 HE0340-2703 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 302 HE0340-2703 STIS/C ACQ/PEA 52X0.1 MIRROR 1 11.0 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 303 HE0340-2703 STIS/F ACCUM 52X0.1 G140M 1222 1 30 M EXPAND UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 304 HE0340-2703 STIS/F ACCUM 52X0.1 G140M 1222 1 45 M EXPAND UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9378( 2) - 02/18/02 10:41 - [ 7] Summary Form for Proposal 9378 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CHECKBOX=9 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements EXPAND ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names MS0337.1-2645 MS0335.4-2618 HE0340-2703 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1222 ------------------------------------------------------------------------------------------------------------------------------------