9040( 2) - 02/08/01 08:49 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9040 Version: 2 Check-in Date: 08-Feb-2001 08:48:45 1.Proposal Title: Baryons in intermediate redshift (z > 1) OVI absorbers ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 10 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Dieter Reimers Universitat Hamburg, Hamburger Sternwarte CoI: Dr. Robert Baade Hamburger Sternwarte N CoI: Dr. Hans-Juergen Hagen Hamburger Sternwarte Y CoI: Dr. Sebastian Lopez Universidad de Chile N CoI: Dr. David Tytler University of California San Diego N ------------------------------------------------------------------------------------ 5. Abstract We propose to search for intervening OVI absorption systems in two further extremely UV bright intermediate redshift QSOs (HS 0747 + 4259, z = 1.9, V = 15.6; HS 0818+2554, z = 1.5, V = 15.4) using the STIS E230M Echelle mode. The scientific aim is to measure the baryonic fraction in the warm-hot intergalactic medium at redshifts 1 <=q z <=q 1.8. Present existing data on HE 0515-4414 taken also with STIS E230M seem to indicate that the baryonic fraction at z = 1.5 is lower by a factor of ~ 15 than the high value found by Tripp et al. (2000) for z < 0.3. Our results need to be confirmed by more lines of sight, and we plan to test hierarchical structure formation models which predict a rapid evolution between z = 1.5 and z = 0. ------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 2] Observations Description ------------------------ We propose to take STIS E230M medium resolution (30 000) Echelle spectra in the range 2100 to 2900 Angstrom (one setting). A S/N around 15 is necessary to be able to detect weak OVI doublets with log N (OVI) >= 13.5 in the UV. With a flux of 4 \cdot 10^-15 erg cm^-2 s^-1 AA ^-1 at 2500 Angstrom an exposure time of 51 000 s or roughly 19 orbits is necessary (including STIS overheads and reacquisition) for each QSO, altogether 38 orbits. Real Time Justification ----------------------- We will apply for ESO VLT/UVES observations both in European (ESO) time and/or Chilenean time (S. Lopez) in order to get high-resolution (50 000) spectra down to the atmospheric limit. For HS 747+4259, D. Tytler will provide Keck-HIRES spectra. Our experience with the HE 0515-4414 STIS+UVES observations has shown that the additional CIV observations of OVI absorbers are important/essential for the interpretation of the ionization mechanism and possible improvements of the determination of the ionization fraction OVI/O. Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 GALAXY, QSO RA=07H 50M 54.63S +/- 0.01S, 2000. Z=1.9 V = 15.6 DEC=42D 52' 19.6" +/- 1", PLATE- B-V = 0.4 ID=01H9 Coordinate Source: GSC_SURVEY_PLATE 2 HS0810+2554 GALAXY, QSO RA=08H 13M 31.32S +/- 0.01S, 2000. Z=1.5 V = 15.4 DEC=25D 45' 02.5" +/- 1", PLATE- B-V = 0.4 ID=02UG Coordinate Source: GSC_SURVEY_PLATE 9040( 2) - 02/08/01 08:49 - [ 4] Visit: 01 Visit Priority: Visit Requirements: GROUP 1-6 WITHIN 30D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 3 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 7] 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 8] 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 9] 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0747+4259 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0747+4259 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 10] Visit: 11 Visit Priority: Visit Requirements: GROUP 11-16 WITHIN 30D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0810+2554 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 3 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 11] Visit: 12 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0810+2554 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 12] Visit: 13 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0810+2554 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 13] Visit: 14 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0810+2554 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 14] Visit: 15 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0810+2554 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 15] Visit: 16 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HS0810+2554 STIS/C ACQ F28X50L MIRROR 1 1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 1 2500 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 HS0810+2554 STIS/N ACCUM 0.2X0.2 E230M 2561 2 3000 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9040( 2) - 02/08/01 08:49 - [ 16] Summary Form for Proposal 9040 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 1-6 WITHIN 30D GROUP 11-16 WITHIN 30D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E230M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HS0747+4259 HS0810+2554 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 2561 ------------------------------------------------------------------------------------------------------------------------------------