11160( 3) - 05/11/07 06:52 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11160 Version: 3 Check-in Time: 11-May-2007 10:52:04 STScI Edit Number: 1 Title Escape fraction and stellar populations in a highly magnified Lyman-Break Galaxy ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Johan Richard California Institute of Technology CoI: Dr. Ian R. Smail University of Durham N CoI: Dr. Mark Swinbank University of Durham N CoI: Dr. Jean-Paul Kneib Observatoire de Marseille N CoI: Prof. Richard S. Ellis California Institute of Technology N CoI: Mr. Daniel P. Stark California Institute of Technology N CoI: Dr. Alastair C. Edge University of Durham N CoI: Dr. Philip J. Marshall University of California - Santa Barbara N CoI: Dr. Harald Ebeling University of Hawaii N CoI: Ms. Sherry H. Suyu California Institute of Technology N CoI: Ms. Kristen Coppin University of British Columbia N ------------------------------------------------------------------------------------ Abstract Understanding how star-forming galaxies contribute to cosmic reionization is one of the frontiers of observational cosmology. A key ingredient in this issue is measuring the escape fraction of Lyman-continuum photons in high redshift galaxies (z>3). Gravitationally lensed Lyman-break galaxies (LBGs) act as important laboratories for studying the resolved physical properties at sub-kpc scales with high signal-to-noise. Correlating the local escape fraction with physical parameters derived from stellar population modeling (such as the star formation rate, age and reddening) will offer new insights into understanding the physical processes involved with the production of ionizing photons. We propose here follow-up observations of the "Cosmic Eye", a remarkable, highly magnified (x 30), Lyman-break galaxy at z~3.07 using WFPC2 and NICMOS. Deep ultraviolet WFPC2 imaging will provide a detailed study of variations in the escape fraction, while WFPC2 and NICMOS/NIC2 imaging will complement the current broad-band detections to allow a precise modeling of the spatially-dependent spectral energy distribution. This will allow the first comprehensive analysis between the escape fraction, the local SED and the dynamics of a distant galaxy. ------------------------------------------------------------------------------------ 11160( 3) - 05/11/07 06:52 - [ 2] Observations Description ------------------------ The first objective of our program requires very deep imaging in the F336W (U) band, using the Wide Field Planetary Camera. From the LRIS spectrum obtained on several parts of the arc and the average f1500/f900 value recently derived by Shapley et al. (2006) in their sample of LBGs, we estimate the surface brightness of the Cosmic Eye to be U~24 mag arcsec-2 (AB). Using the Exposure Time Calculator of WFPC2, and taking into account the visibility of the Cosmic Eye (52 min. per orbit) and the overheads ~12 min, we evaluated that a signal- to-noise sigma~4 is achievable in 6 orbits (14.4 ks). Multiple WFPC2/F336W exposures will be used in ACCUM mode, using a dithering pattern to eliminate detector artifacts and provide an adequate sampling of the PSF. In order to correlate the measured escape fraction with the physical properties (star formation rate, age, reddening) in each region of the arc, we require additional observations with WFPC2 and NICMOS. Using the exposure time calculator and the previous visibility and overhead estimates, 1 orbit integration with WFPC2 will reach ~30 sigma in the F814W filters, matching the depth of our current F606W snapshot image. Multiple exposures will be taken in each filter, using a DITHER-BOX dithering pattern to provide an accurate subsampling of the PSF and eliminate detector artifacts. We propose to use the NIC2 channel on NICMOS for the observations in the F110W and F160W band, since the Cosmic Eye is easily covered by the size of this camera, and the high resolution is critical for the purpose of this project. Based on the observed integrated colors in the SDSS and NIRC/K images, as well as the LRIS spectrum, we estimate total AB magnitudes of I~19.8 J~19.3 and H~19.1 for the combined arcs, with a surface area of ~0.7 arcsec2. According to the NICMOS Exposure Time Calculator, and based on the photometric estimates given above, a signal- to-noise per pixel sigma~30-40 is reachable in a single HST orbit. A dithering pattern with multiple exposures will ensure removal of dead or non-calibrated pixels on the detectors, improve the sampling of the PSF in the F110W filter, as well as prevent post-SAA cosmic ray persistance. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11160( 3) - 05/11/07 06:52 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 COSMICEYE GALAXY, GRAVITATIONAL RA=21H35M12.7340S +/- 0.5", J2000 V = 20.3+/-0.1 LENS, HIGH REDSHIFT DEC=-01D01'43.94" +/- 0.5" U=24.0 +/- 0.2 mag.arcsec-2 I(814) = GALAXY 19.8 +/- 0.1 J (110) =19.3 +/- 0.1 H(160)=19.1 +/- 0.1 surface=0.7 arcsec2 Reference Frame: ICRS 11160( 3) - 05/11/07 06:52 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFPC2-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.559017 Line_Spacing 0.559017 Coordinate_Frame POS-TARG Pattern_Orient 26.56505 Angle_Between_Sides 143.130102 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 11160( 3) - 05/11/07 06:52 - [ 5] Visit: 01 Visit Priority: Visit Requirements: GROUP 01, 02, 03, 04, 05, 06 WITHIN 30.0D 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 COSMICEYE WFPC2 IMAGE WFALL F336W CR-SPLIT=NO 1 2600 S ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F336W none none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 6] Visit: 02 Visit Priority: Visit Requirements: 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 COSMICEYE WFPC2 IMAGE WFALL F336W CR-SPLIT=NO 1 2600 S POS TARG 1, 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F336W none none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 7] Visit: 03 Visit Priority: Visit Requirements: 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 COSMICEYE WFPC2 IMAGE WFALL F336W CR-SPLIT=NO 1 2600 S POS TARG 0, 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F336W none none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 8] Visit: 04 Visit Priority: Visit Requirements: 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 COSMICEYE WFPC2 IMAGE WFALL F336W CR-SPLIT=NO 1 2600 S POS TARG -1, 0 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F336W none none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 9] Visit: 05 Visit Priority: Visit Requirements: 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 COSMICEYE WFPC2 IMAGE WFALL F336W CR-SPLIT=NO 1 2600 S POS TARG -1,-1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F336W none none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 10] Visit: 06 Visit Priority: Visit Requirements: 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 COSMICEYE WFPC2 IMAGE WFALL F336W CR-SPLIT=NO 1 2600 S POS TARG 1,-1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F336W none none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 11] Visit: 07 Visit Priority: Visit Requirements: 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 COSMICEYE WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 400 S PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 WFPC2 IMAGE WFALL F814W 1 none none none 1 N/A COSMICEYE 1 WFPC2 IMAGE WFALL F814W 2 none none none 1 N/A COSMICEYE 1 WFPC2 IMAGE WFALL F814W 3 none none none 1 N/A COSMICEYE 1 WFPC2 IMAGE WFALL F814W 4 none none none 1 N/A 11160( 3) - 05/11/07 06:52 - [ 12] Visit: 08 Visit Priority: Visit Requirements: 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 COSMICEYE NIC2 MULTIAC NIC2 F110W SAMP-SEQ=SPARS64,NSAMP=7 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 2 COSMICEYE NIC2 MULTIAC NIC2 F110W SAMP-SEQ=SPARS64,NSAMP=6 1 DEF POS TARG 0.7, 1.5 CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 COSMICEYE NIC2 MULTIAC NIC2 F110W SAMP-SEQ=SPARS64,NSAMP=6 1 DEF POS TARG -0.7,-1.5 CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 COSMICEYE NIC2 MULTIAC NIC2 F110W SAMP-SEQ=SPARS64,NSAMP=6 1 DEF POS TARG 1.5, 0.7 CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 COSMICEYE NIC2 MULTIAC NIC2 F160W SAMP-SEQ=SPARS64,NSAMP=7 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 COSMICEYE NIC2 MULTIAC NIC2 F160W SAMP-SEQ=SPARS64,NSAMP=7 1 DEF POS TARG 0.7, 1.5 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 COSMICEYE NIC2 MULTIAC NIC2 F160W SAMP-SEQ=SPARS64,NSAMP=7 1 DEF POS TARG -0.7,-1.5 CUM ------------------------------------------------------------------------------------------------------------------------------------ 8 COSMICEYE NIC2 MULTIAC NIC2 F160W SAMP-SEQ=SPARS64,NSAMP=7 1 DEF POS TARG 1.5, 0.7 CUM ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 1 NIC2 MULTIAC NIC2 F110W none none none none 1 N/A CUM COSMICEYE 2 NIC2 MULTIAC NIC2 F110W none none none none 1 N/A CUM COSMICEYE 3 NIC2 MULTIAC NIC2 F110W none none none none 1 N/A CUM COSMICEYE 4 NIC2 MULTIAC NIC2 F110W none none none none 1 N/A CUM COSMICEYE 5 NIC2 MULTIAC NIC2 F160W none none none none 1 N/A CUM 11160( 3) - 05/11/07 06:52 - [ 13] 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSMICEYE 6 NIC2 MULTIAC NIC2 F160W none none none none 1 N/A CUM COSMICEYE 7 NIC2 MULTIAC NIC2 F160W none none none none 1 N/A CUM COSMICEYE 8 NIC2 MULTIAC NIC2 F160W none none none none 1 N/A CUM 11160( 3) - 05/11/07 06:52 - [ 14] Summary Form for Proposal 11160 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFALL NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO SAMP-SEQ=SPARS64 NSAMP=7 NSAMP=6 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 01, 02, 03, 04, 05, 06 WITHIN 30.0D; POS TARG 1, 1; POS TARG 0, 1; POS TARG -1, 0; POS TARG -1,-1; POS TARG 1,-1; PATTERN 1 1; POS TARG 0.7, 1.5; POS TARG -0.7,-1.5; POS TARG 1.5, 0.7; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F814W F110W F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names COSMICEYE ------------------------------------------------------------------------------------------------------------------------------------