13356( 2) - 26-Jun-2013 18:15:08 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13356 Version: 2 Check-in Time: 26-Jun-2013 18:15:08 STScI Edit Number: 0 Title A Candidate Gravitationally Lensed Quasar at z=6.09 ------------------------------------------------------------------------------------ Type Cycle GO 21 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Ian McGreer University of Arizona Y CoI: Prof. Xiaohui Fan University of Arizona N CoI: Dr. Linhua Jiang Arizona State University N CoI: Dr. Michael A. Strauss Princeton University N CoI: Dr. Gordon T. Richards Drexel University N CoI: Prof. Zoltan Haiman Columbia University in the City of New N York CoI: Prof. Donald P. Schneider The Pennsylvania State University N ------------------------------------------------------------------------------------ Abstract We have obtained WFC3/IR images of nearly half of the known quasars at z~6 through a Cycle 18 SNAP program. During the latter part of the Cycle we identified a candidate gravitationally lensed quasar, SDSSJ1602+4228, at z=6.09. The short duration SNAP exposure shows that the central arcsecond is resolved into multiple emission features, which we interpret as two lensed images of the z=6 quasar and the lens galaxy. However, from the single band image the nature of the components is inconclusive. We propose a brief (two orbit) follow-up program that will include imaging in three bands: WFC3/IR Y and H, and ACS/WFC R-band. The combination of infrared and optical imaging will allow us to use color information to isolate the quasar images, lens galaxy, or any contaminating foreground objects. The confirmation of even one lensed quasar among the SNAP sample has strong implications for the shape of the quasar luminosity function at z=6, with further implications for expected source counts at higher redshift, as well as models for black hole growth in the early Universe. ------------------------------------------------------------------------------------ Observations Description ------------------------ J1602+4228 is a z=6.09 quasar that is a candidate gravitational lens based on the morphology of a WFC3 SNAP image obtained in Cycle 18. The SNAP image shows a bright PSF component associated with the known quasar, as well as a putative secondary PSF component and extended emission on ~1'' scales. This program will test the lensing hypothesis for this object by using optical and infrared color information to discriminate foreground objects from those at the redshift of the quasar. One orbit with WFC3/IR will be split between F105W and F160W. The observations will use optimal dithering with a 4-pt box pattern and the WFC3 IR aperture. The integrations in each band are 7xSPARS50 for 350s at each dither point. A second orbit will use ACS/WFC with the F606W filter, and will similarly employ a 4-pt box pattern with 567s individual exposure times. 13356( 2) - 26-Jun-2013 18:15:08 - [ 2] Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 13356( 2) - 26-Jun-2013 18:15:08 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ160253. GALAXY, GRAVITATIONAL RA=16H02M53.9800S +/- 0.1", J2000 z(AB)=19.9 9+422824 LENS, HIGH REDSHIFT DEC=+42D28'24.80" +/- 0.1" GALAXY, QSO Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13356( 2) - 26-Jun-2013 18:15:08 - [ 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 NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13356( 2) - 26-Jun-2013 18:15:08 - [ 5] Visit: 01 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ160253 ACS/WFC ACCUM WFC F606W 1 576 S PATTERN 1 1 .9+422824 (2304 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ160253.9+42282 1 ACS/WFC ACCUM WFC F606W 1 none none none 1 N/A 4 SDSSJ160253.9+42282 1 ACS/WFC ACCUM WFC F606W 2 none none none 1 N/A 4 SDSSJ160253.9+42282 1 ACS/WFC ACCUM WFC F606W 3 none none none 1 N/A 4 SDSSJ160253.9+42282 1 ACS/WFC ACCUM WFC F606W 4 none none none 1 N/A 4 13356( 2) - 26-Jun-2013 18:15:08 - [ 6] Visit: 02 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ160253 WFC3/IR MULTIAC IR F105W NSAMP=7, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 1 .9+422824 CUM (1211.74 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ160253 WFC3/IR MULTIAC IR F160W NSAMP=7, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 2 .9+422824 CUM (1211.74 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 | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ160253.9+42282 1 WFC3/IR MULTIAC IR F105W 1 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 1 WFC3/IR MULTIAC IR F105W 2 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 1 WFC3/IR MULTIAC IR F105W 3 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 1 WFC3/IR MULTIAC IR F105W 4 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 2 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 2 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 2 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A 4 CUM SDSSJ160253.9+42282 2 WFC3/IR MULTIAC IR F160W 4 none none none 1 N/A 4 CUM 13356( 2) - 26-Jun-2013 18:15:08 - [ 7] Summary Form for Proposal 13356 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=7, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1, PATTERN 2 1, PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F105W, F160W, F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSSJ160253.9+422824 ------------------------------------------------------------------------------------------------------------------------------------