10159( 3) - 07/06/04 17:01 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10159 Version: 3 Check-in Date: 06-Jul-2004 20:58:53 1.Proposal Title: Characterizing the Sources Responsible for Cosmic Reionization ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Richard S. Ellis California Institute of Technology CoI: Dr. Jean-Paul Kneib California Institute of Technology N CoI: Mr. Michael Santos University of Cambridge N CoI: Dr. Robert Fosbury European Southern Observatory - Germany N ------------------------------------------------------------------------------------ 6. Abstract Our group has demonstrated the role that massive clusters of galaxies, acting as powerful cosmic lenses, can play in locating sources with modest mass and star formation rate beyond redshifts z~5-6 likely to be representative of those responsible for cosmic reionization. The large magnifications, possible in the critical regions of well-constrained clusters, bring sources into view that would lie at or beyond the limits of conventional exposures such as the UDF. Recently, using deep ACS and NICMOS imaging, we have located a low mass source at z=7.05 whose UV continuum slope is apparently steeper than for normal star-forming galaxies. We propose a deep ACS grism exposure to confirm the nature of this source and further ACS and NICMOS imaging of well-studied clusters to locate further examples. The grism spectroscopy will conclusively determine the UV SED of this source and our 3- color survey will constrain the redshift, star-formation rate, and SED of additional 66.5, with more than 2.5 Msun/yr of star formation (our survey limit). Before the advent of the next generation of observational facilities, our search technique may represent the only way to reliably select and characterize the likely population of galaxies during the epoch of reionization. ------------------------------------------------------------------------------------ 10159( 3) - 07/06/04 17:01 - [ 2] Observations Description ------------------------ This programme is aiming to do deep grism observations of a cluster field to get the spectrum of a redshift z~7 lensed galaxy in the cluster Abell 2218 (Kneib et al 2004). The angle was chose to minimize the overlap of the z~7 object with the other galaxy spectra. These observation is conducted in 2 visits, the first one with 4 orbits, the second one with 3 orbits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10159( 3) - 07/06/04 17:01 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ABELL2218 CLUSTER OF GALAXIES, RA=16H35M51.4S +/- 0.1", J2000 V = 27.0 GRAVITATIONAL LENS DEC=+66D12'25.0" +/- 0.1" Coordinate Source: GUIDE_STAR_CATALOG 10159( 3) - 07/06/04 17:01 - [ 4] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE; GUID TOL 0.1"; DROP TO GYRO IF NECESSARY ; ORIENT 19.0D TO 25.0 D On Hold Comments: Additional Comments: This programme is aiming to do deep grism observations of a cluster field to get the spectrum of a redshift z~7 lensed galaxy in the cluster Abell 2218 (Kneib et al 2004). The angle was chose to minimize the overlap of the z~7 object with the other galaxy spectra. These observation is conducted in 2 visits, the first one with 4 orbits, the second one with 3 orbits. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 0, 0 ------------------------------------------------------------------------------------------------------------------------------------ 2 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2400 S POS TARG 0, 0 ------------------------------------------------------------------------------------------------------------------------------------ 3 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 3.76, 3.71 ------------------------------------------------------------------------------------------------------------------------------------ 4 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2500 S POS TARG 3.76, 3.71 ------------------------------------------------------------------------------------------------------------------------------------ 5 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 7.495, 7.45 ------------------------------------------------------------------------------------------------------------------------------------ 6 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2500 S POS TARG 7.495, 7.45 ------------------------------------------------------------------------------------------------------------------------------------ 7 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 11.255, 11.18 ------------------------------------------------------------------------------------------------------------------------------------ 8 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2500 S POS TARG 11.255, 11.18 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 none none none none 1 tbd 01 2 none none none 1 1 tbd 01 2 none none none 2 1 tbd 01 3 none none none none 2 tbd 01 4 none none none 1 2 tbd 01 4 none none none 2 2 tbd 01 5 none none none none 3 tbd 01 6 none none none 1 3 tbd 01 6 none none none 2 3 tbd 01 7 none none none none 4 tbd 01 8 none none none 1 4 tbd 01 8 none none none 2 4 tbd 10159( 3) - 07/06/04 17:01 - [ 5] Visit: 02 Visit Priority: Visit Requirements: PCS MODE FINE; GUID TOL 0.1"; DROP TO GYRO IF NECESSARY ; ORIENT 19.0D TO 25.0 D On Hold Comments: Additional Comments: This programme is aiming to do deep grism observations of a cluster field to get the spectrum of a redshift z~7 lensed galaxy in the cluster Abell 2218 (Kneib et al 2004). The angle was chose to minimize the overlap of the z~7 object with the other galaxy spectra. These observation is conducted in 2 visits, the first one with 4 orbits, the second one with 3 orbits. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 0.125, 0.125 ------------------------------------------------------------------------------------------------------------------------------------ 2 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2400 S POS TARG 0.125, 0.125 ------------------------------------------------------------------------------------------------------------------------------------ 3 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 5.719, 5.705 ------------------------------------------------------------------------------------------------------------------------------------ 4 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2500 S POS TARG 5.719, 5.705 ------------------------------------------------------------------------------------------------------------------------------------ 5 ABELL2218 ACS/WFC ACCUM WFCENTER F814W CR-SPLIT=NO 1 184 S POS TARG 11.38, 11.305 ------------------------------------------------------------------------------------------------------------------------------------ 6 ABELL2218 ACS/WFC ACCUM WFCENTER G800L CR-SPLIT=2,AUTOIMAGE=NO 1 2500 S POS TARG 11.38, 11.305 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 none none none none 1 tbd 02 2 none none none 1 1 tbd 02 2 none none none 2 1 tbd 02 3 none none none none 2 tbd 02 4 none none none 1 2 tbd 02 4 none none none 2 2 tbd 02 5 none none none none 3 tbd 02 6 none none none 1 3 tbd 02 6 none none none 2 3 tbd 10159( 3) - 07/06/04 17:01 - [ 6] Summary Form for Proposal 10159 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFCENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO AUTOIMAGE=NO CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE; GUID TOL 0.1"; DROP TO GYRO IF NECESSARY ; ORIENT 19.0D TO 25.0 D POS TARG 0, 0 POS TARG 3.76, 3.71 POS TARG 7.495, 7.45 POS TARG 11.255, 11.18 POS TARG 0.125, 0.125 POS TARG 5.719, 5.705 POS TARG 11.38, 11.305 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W G800L ------------------------------------------------------------------------------------------------------------------------------------ Target Names ABELL2218 ------------------------------------------------------------------------------------------------------------------------------------