10831( 3) - 11/28/06 10:01 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10831 Version: 3 Check-in Time: 28-Nov-2006 15:01:04 STScI Edit Number: 1 Title A new wide-separation Einstein Cross at z=2.7 ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 15 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Leonidas Moustakas Jet Propulsion Laboratory CoI: Dr. Daniel Stern Jet Propulsion Laboratory N CoI: Dr. Adam S. Bolton Smithsonian Institution Astrophysical N Observatory CoI: Prof. Scott Burles Massachusetts Institute of Technology N CoI: Dr. Arjun Dey National Optical Astronomy Observatories, N AURA CoI: Prof. Hyron Spinrad University of California - Berkeley N ------------------------------------------------------------------------------------ Abstract We propose ACS F555W and F814W imaging observations of a new wide-separation Einstein Cross selected from SDSS spectroscopy through a bright anomalous emission line and confirmed recently with Keck imaging and spectroscopy. The source galaxy is a moderately luminous (L~0.2L*) Lyman-alpha emitter at z=2.699, which is magnified and extended by more than a factor of twenty, making it one of the most accessible high-redshift bright Ly-a emitters on the sky. Its apparent flux is only 1.2 magnitudes fainter than MS1612-cB58, making this an ideal system for detailed study of the metallicity and initial mass function of a high-redshift star forming galaxy. The Einstein Radius is ~1.8arcsec, one of the widest known, making future spectroscopic ground-based followup optimal. This angle subtends ~5 kpc at the lens galaxy at z=0.331. The high resolution, high signal to noise imaging we propose to obtain will allow us to build accurate lensing models, including source reconstructions; combined with existing and planned Keck spectroscopy, will make possible a map of the host dark matter halo density profile to greater than one effective light radius; and will reveal lower surface brightness features associated with the bright star-forming knot lensed into the Cross. Finally, it will be an exquisite Hubble Heritage galaxy, which will be indispensable for many other applications. We are requesting a very modest proprietary period, in order to provide high-level reductions and ancillary data publically available simultaneously. ------------------------------------------------------------------------------------ 10831( 3) - 11/28/06 10:01 - [ 2] Observations Description ------------------------ We are obtaining deep images of the target Einstein Cross with one orbit each in F555W and F814W with ACS-WFC, with aperture set to WFC1. In each orbit we use ACS-WFC-DITHER-BOX with 4 points and the default spacings and no CR-SPLIT. Each band is observed for 4x522s = 2088s. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10831( 3) - 11/28/06 10:01 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1011+01 GALAXY, GRAVITATIONAL RA=10H11M29.4900S +/- 0.1", J2000 Z = V = 22.0 43 LENS DEC=+01D43'23.30" +/- 0.1" 0.331 I=21.2 Reference Frame: Other: SDSS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0 0.0 0.0 10831( 3) - 11/28/06 10:01 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.265 Line_Spacing 0.187 Coordinate_Frame POS-TARG Pattern_Orient 20.67 Angle_Between_Sides 69.05 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 10831( 3) - 11/28/06 10:01 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 285.0D TO 340.0 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1011+0 ACS/WFC ACCUM WFC2 F555W CR-SPLIT=NO 1 522 S PATTERN 1 1 143 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 1 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 2 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 3 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 4 none none none 1 N/A 10831( 3) - 11/28/06 10:01 - [ 6] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENT AS 01 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1011+0 ACS/WFC ACCUM WFC2 F814W CR-SPLIT=NO 1 522 S PATTERN 1 1 143 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F814W 1 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F814W 2 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F814W 3 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F814W 4 none none none 1 N/A 10831( 3) - 11/28/06 10:01 - [ 7] Visit: 51 Visit Priority: Visit Requirements: ORIENT 285.0D TO 340.0 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1011+0 ACS/WFC ACCUM WFC2 F555W CR-SPLIT=NO 1 522 S PATTERN 1 1 143 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 1 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 2 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 3 none none none 1 N/A SDSSJ1011+0143 1 ACS/WFC ACCUM WFC2 F555W 4 none none none 1 N/A 10831( 3) - 11/28/06 10:01 - [ 8] Summary Form for Proposal 10831 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 285.0D TO 340.0 D; PATTERN 1 1; SAME ORIENT AS 01; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSSJ1011+0143 ------------------------------------------------------------------------------------------------------------------------------------