9734( 10) - 05/19/03 11:11 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9734 Version: 10 Check-in Date: 19-May-2003 11:09:51 1.Proposal Title: Leaky IGM at z=6 or Lyman Alpha Galaxy at z=5? ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 12 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Dr. Richard L. White Space Telescope Science Institute CoI: Dr. Robert Becker University of California - Davis N CoI: Dr. Xiaohui Fan University of Arizona N ------------------------------------------------------------------------------------ 5. Abstract We propose to image the z=6.4 quasar SDSS J1148+5251 with the ACS using a narrow- band ramp filter in the Lyman Beta Gunn-Peterson absorption trough. The observations will distinguish between two possible explanations for several weak emission features seen in a long-exposure Keck spectrum. Either there are high-ionization bubbles in the IGM at z=6 that allow light from the quasar to leak through the Lyman Beta forest, or there is an intervening Lyman alpha emitting galaxy at z=5 (as suggested by C IV absorption at the same redshift.) If there is a galaxy, it may be associated with a lensing mass concentration at z=5. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe SDSS J1148+5251 for two orbits with ACS using the narrow-band (2% bandpass) ramp filter. Most of the time (72 min) goes to an observation with the filter centered at 7220 A. We also obtain a short exposure image (12 min) of the quasar in Ly alpha, which will allow us to determine an accurate position. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9734( 10) - 05/19/03 11:11 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1148+52 GALAXY, QSO RA=11H48M16.64S +/- 0.1", J2000 Z = 6.37 V = 25.0 51 DEC=+52D51'50.3" +/- 0.1" Coordinate Source: Other_Source: SDSS Comments: other fluxes: i=23.3, J=18.3, z=20.0 9734( 10) - 05/19/03 11:11 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.146 Coordinate_Frame POS-TARG Pattern_Orient 47.17 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 9734( 10) - 05/19/03 11:11 - [ 4] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE SCHED 30% 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 SDSSJ1148+5 ACS/WF ACCUM WFC FR716N 7220 CR-SPLIT=NO 1 1305 S PATTERN 1 1 251 C ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ1148+5 ACS/WF ACCUM WFC FR716N 7220 CR-SPLIT=NO 1 823 S PATTERN 1 2 251 C ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ1148+5 ACS/WF ACCUM WFC FR914M 9050 CR-SPLIT=NO 1 360 S PATTERN 1 3 251 C ------------------------------------------------------------------------------------------------------------------------------------ 9734( 10) - 05/19/03 11:11 - [ 5] Summary Form for Proposal 9734 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE SCHED 30% PATTERN 1 1 PATTERN 1 2 PATTERN 1 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements FR716N FR914M ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSSJ1148+5251 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 7220 9050 ------------------------------------------------------------------------------------------------------------------------------------