9441( 7) - 09/02/03 12:07 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9441 Version: 7 Check-in Date: 02-Sep-2003 12:05:33 1.Proposal Title: Zinc Abundances in Damped Ly-Alpha Systems at z < 0.5: A Missing Link in the Chemical History of Galaxies ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Prof. Varsha Kulkarni University of South Carolina CoI: Dr. S. Michael Fall Space Telescope Science Institute N CoI: Prof. Donald York University of Chicago N CoI: Prof. James Truran University of Chicago N CoI: Dr. Daniel Welty University of Chicago N CoI: Prof. James Lauroesch Northwestern University N ------------------------------------------------------------------------------------ 5. Abstract The evolution of metallicity in damped Lyman alpha (DLA) quasar absorption systems is an important constraint on the global star formation history of the universe, but remains a big puzzle at present. The H I column density weighted mean metallicity in DLAs is expected to rise to solar values at low redshifts, based on cosmic chemical evolution models, because the mass-weighted mean metallicity of local galaxies is near- solar. However, current DLA abundance studies are highly uncertain and cannot distinguish between evolution and no evolution in the mean metallicity at redshifts 0.4 < z < 3.5. The existing data are particularly incomplete because no Zn measurements exist for z < 0.4, and only 2 exist for z < 0.5, which spans the past 35-45 % of the age of the universe. To pin down the cosmic age-metallicity relation all the way to the present epoch, we propose to measure Zn abundances in five DLAs at 0.1 < z < 0.5. We propose to use HST STIS because it is the only existing instrument that can measure the necessary UV lines. Our observations will clearly distinguish between no metallicity evolution vs. the predicted evolution. Our data will also provide Cr measurements, which will help to estimate the dust abundance. The proposed observations are crucial for tying together the absorption and emission histories of gas and stars in galaxies and for clarifying the relation of DLAs to present-day galaxies. ------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 2] Observations Description ------------------------ We will use the G230M, G230MB, or G430M gratings on STIS, which have the moderately high spectral resolution and wavelength coverage necessary for the abundance determinations. The lines of interest are Zn II Lambda Lambda 2026, 2062 and Cr II Lambda Lambda 2056, 2062, 2066, which occur in the range of 2211-3145 Angstroms for the DLA absorbers in our sample. We will use the 52"x0.2" slit to get a good compromise between spectral resolution and photometric throughput. In the case of Q0235+164, the narrow slit will also help to decrease contamination of the quasar spectrum by the two fainter somewhat extended objects that lie at about 1.3" and 2" away from the quasar. The observations of Q0235+164 need to be scheduled after we notify STScI that this object is in a bright phase, based on our ground-based photometric monitoring of this variable object. If Q0235+164 does not go into a bright phase by August 1, 2003, we will move its 3 orbits to Q0952+179. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 Q0235+164 GALAXY, QUASAR RA=02H 38M 38.9S +/- 0.05S, J2000 Z=0.940 V = 15.5 DEC=16D 36' 59.7" +/- 0.5", B-V = 0.96 PLATE-ID=01G9 U-B = 0.14 E(B-V) = 0.079 Coordinate Source: GSC_SURVEY_PLATE Comments: This is a BL Lac object. V varies between 15.5 and 18.5. Z_abs=0.524. 2 Q0738+313 GALAXY, QUASAR RA=07H 41M 10.70S +/- 0.05S, J2000 Z=0.635 V = 16.14 DEC=31D 11' 59.8" +/- 0.5", B-V = 0.07 PLATE-ID=000I U-B = -0.61 E(B-V) = 0.047 F(2211)=2.6e-15 F(2474)=2.7e-15 Coordinate Source: GSC_SURVEY_PLATE Comments: Z_abs=0.0912, 0.2212 3 Q0827+243 GALAXY, QUASAR RA=08H 30M 52.1S +/- 0.05S, J2000 Z=0.939 V = 17.26 DEC=24D 10' 59.5" +/- 0.5", B-V = 0.36 PLATE-ID=02UG U-B = -0.79 E(B-V) = 0.033 F(3089)=2.5e-15 Coordinate Source: GSC_SURVEY_PLATE Comments: Z_abs=0.5247 4 Q0952+179 GALAXY, QUASAR RA=09H 54M 56.8S +/- 0.05S, J2000 Z = V = 17.23 DEC=17D 43' 31.3" +/- 0.5", 1.472 B-V = 0.08 PLATE-ID=021L U-B = -0.74 E(B-V) = 0.027 F(2500)=1.0e-15 Coordinate Source: GSC_SURVEY_PLATE Comments: Z_abs=0.2378 9441( 7) - 09/02/03 12:07 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.4 Coordinate_Frame POS-TARG Pattern_Orient 90 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.4 Coordinate_Frame POS-TARG Pattern_Orient 90 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.4 Coordinate_Frame POS-TARG Pattern_Orient 90 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 5] Visit: 01 Visit Priority: Visit Requirements: SCHED 100% ON HOLD On Hold Comments: This visit is to be scheduled after we notify STScI that it is ok to observe this target. The target is a BL Lac object with variable flux and will be monitored photometrically by us from ground-based observations to determine when it goes into a bright phase. A 3 to 4 weeks notice will be given before scheduling of this object. If the observation can be scheduled about 2 weeks after we notify STScI, that would of course be preferable (to maximize the chance to catch the quasar in a bright phase), but scheduling after 3-4 weeks would be alright. Finally, if Q0235+164 does not go into a bright phase by August 1, 2003, the 3 orbits of this visit will be moved to Q0952+179. Additional Comments: We have used 100% schedulability and avoided orient constraints to aid with the scheduling of this visit at a 3-4 weeks notice after the target goes into a bright phase. In the bright phase of this quasar, any possible contamination from the two much fainter diffuse objects located at about 1.3" and 2" from the quasar should be minimal, irrespective of the orient used. The target acquisition exposure time is chosen, using the observed spectral shape for this quasar from archival HST spectra, so as to allow detection of the quasar at a S/N > 45 if the object has V=17 at the time of observation; but we have checked that there will be no saturation of the detector if the target has V=15.5 at the time of observation. Since the two diffuse sources are fainter than about 20th magnitude, and the quasar is rarely fainter than 19th magnitude, the likelihood of the target acquisition software acquiring the diffuse objects instead of the quasar is expected to be small, given that the observations will be scheduled a few weeks after we confirm the quasar is in a bright phase. However, if our ground-based photometric monitoring suggests that the STIS target acquisition of the quasar may be more difficult than we estimate, we may choose to acquire a nearby star and then offset from that. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 100 Q0235+164 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 20 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 110 Q0235+164 STIS/C ACCUM 52X0.2E G430M 3165 CR-SPLIT=3 1 34 M PATTERN 2 110-110 CD 1 ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 6] 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 ------------------------------------------------------------------------------------------------------------------------------------ 300 Q0738+313 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 3 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 310 Q0738+313 STIS/N ACCUM 52X0.2 G230M 2176 1 40 M PATTERN 2 310-310 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 7] 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 ------------------------------------------------------------------------------------------------------------------------------------ 400 Q0738+313 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 3 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 410 Q0738+313 STIS/N ACCUM 52X0.2 G230M 2176 1 40 M PATTERN 1 410-410 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 8] Visit: 04 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 ------------------------------------------------------------------------------------------------------------------------------------ 500 Q0738+313 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 3 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 510 Q0738+313 STIS/N ACCUM 52X0.2 G230M 2257 1 48 M PATTERN 3 510-510 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 9] Visit: 05 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 ------------------------------------------------------------------------------------------------------------------------------------ 600 Q0738+313 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 3 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 610 Q0738+313 STIS/N ACCUM 52X0.2 G230M 2499 1 48 M PATTERN 2 610-610 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 10] Visit: 06 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 ------------------------------------------------------------------------------------------------------------------------------------ 700 Q0738+313 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 3 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 710 Q0738+313 STIS/N ACCUM 52X0.2 G230M 2499 1 48 M PATTERN 1 710-710 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 11] Visit: 07 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 ------------------------------------------------------------------------------------------------------------------------------------ 800 Q0827+243 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 810 Q0827+243 STIS/C ACCUM 52X0.2E G230MB 3115 CR-SPLIT=3 1 37 M PATTERN 2 810-810 CD 1 ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 12] Visit: 08 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 ------------------------------------------------------------------------------------------------------------------------------------ 900 Q0827+243 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 910 Q0827+243 STIS/C ACCUM 52X0.2E G230MB 3115 CR-SPLIT=3 1 36 M PATTERN 1 910-910 CD 1 ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 13] Visit: 09 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 ------------------------------------------------------------------------------------------------------------------------------------ 920 Q0952+179 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 930 Q0952+179 STIS/N ACCUM 52X0.2 G230M 2579 1 38 M PATTERN 2 930-930 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 14] Visit: 10 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 ------------------------------------------------------------------------------------------------------------------------------------ 940 Q0952+179 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 950 Q0952+179 STIS/N ACCUM 52X0.2 G230M 2579 1 45 M PATTERN 2 950-950 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 15] Visit: 11 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 ------------------------------------------------------------------------------------------------------------------------------------ 960 Q0952+179 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 970 Q0952+179 STIS/N ACCUM 52X0.2 G230M 2579 1 45 M PATTERN 3 970-970 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 16] Visit: 21 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 ------------------------------------------------------------------------------------------------------------------------------------ 960 Q0952+179 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 970 Q0952+179 STIS/N ACCUM 52X0.2 G230M 2579 1 45 M POS TARG 0, 0.6 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 17] Visit: 30 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 ------------------------------------------------------------------------------------------------------------------------------------ 980 Q0952+179 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 990 Q0952+179 STIS/N ACCUM 52X0.2 G230M 2579 1 45 M PATTERN 2 990-990 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9441( 7) - 09/02/03 12:07 - [ 18] Summary Form for Proposal 9441 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.2E1 52X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CR-SPLIT=3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% ON HOLD PATTERN 2 110-110 PATTERN 2 310-310 PATTERN 1 410-410 PATTERN 3 510-510 PATTERN 2 610-610 PATTERN 1 710-710 PATTERN 2 810-810 PATTERN 1 910-910 PATTERN 2 930-930 PATTERN 2 950-950 PATTERN 3 970-970 POS TARG 0, 0.6 PATTERN 2 990-990 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G430M G230M G230MB ------------------------------------------------------------------------------------------------------------------------------------ Target Names Q0235+164 Q0738+313 Q0827+243 Q0952+179 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 3165 2176 2257 2499 3115 2579 ------------------------------------------------------------------------------------------------------------------------------------