16484( 2) - 02-Feb-2021 17:42:31 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16484 Version: 2 Check-in Time: 02-Feb-2021 17:42:31 STScI Edit Number: 0 Title First Radio Observations of the Brightest Object at z > 5 ------------------------------------------------------------------------------------ Type Cycle GO 28 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Antony A. Stark Smithsonian Institution Astrophysical Y Observatory CoI: Prof. Michael D. Gladders University of Chicago N CoI: Dr. Matthew Bayliss University of Cincinnati Main Campus N CoI: Prof. Keren Sharon University of Michigan N CoI: Mr. Sasha Brownsberger Harvard University N ------------------------------------------------------------------------------------ Abstract A recently discovered z = 5.04 lensed galaxy, COOLJ1241+2219, has an AB magnitude z = 20.5, making it is the brightest known z > 5 galaxy at OIR wavelengths by a factor of five. It is lensed by a galaxy cluster with spectroscopic z = 1.002, and a preliminary lens model indicates that the mass of that cluster core is ~10^14 solar masses. The observed rest-wavelength UV of the lensed galaxy indicates formation of massive stars in the recent past, yet an upper limit of 2 mJy/beam at 314 GHz from the SMA indicates there is little dust in a warm neutral medium. It is not, therefore, one of the usual SMG detected by millimeter-wave and FIR surveys, it is something new: a galaxy in the early Universe where star formation is already in decline. We propose a first look of this source in the radio at the high end of the VLA Ka band, which includes the CO J=2-1 line, for three 4-hour sessions that should detect the galaxy's remaining star-forming molecular material. A three-orbit joint request to HST will provide data to refine the lens model and allow inversion of the lens to reconstruct the unlensed galaxy. ------------------------------------------------------------------------------------ Observations Description ------------------------ The target is the brightest z>5 galaxy known. It is lensed by a foregound poor galaxy cluster at z=1, into a lensed arc. The lensing configuration suggest that a few tens of arcsecs around the lens center are of most interest, i.e. the target is extended but not large. There are no orient constraints. Observations are one orbit in ACS in F606W, one orbit in ACS with F814W, and one orbit WFC3-IR in F110W and F160W. For each ACS orbit we have programmed a simple 4-point dither sequence. Each exposure is 515 seconds, and the dither sequence is the standard ACS-WRFC-DITHER-BOX. No need to fill the chip gap, since the target fits readily on one chip. We have chosen the chip 2 potining aperture, because that seems to do a slightly better job of likely avoiding a star on the field edges that is in the FOV at some orients. For the WFC3-IR orbit, we want a minimum of 4 dithered images per filter. Going 16484( 2) - 02-Feb-2021 17:42:31 - [ 2] to more than 4 images with reasonably balanced exposure times seemed impossible due to buffer dump contraints; hence we have programmed 4 images per filter using the WFC3-IR-DITHER-BOX-MIN pattern. We will correct for the IR blobs using a model-based flatfielding technique that we have used previously on similar data. Buffer dump contraints limit choices here: we've pushed any extra time from a simple 50/50 split into the F160W filter (which is notionally a bit slower) and used SPARS25 readout in one instance and SPARS50 in the other. ------------------------------------------------------------------------------------ 16484( 2) - 02-Feb-2021 17:42:31 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 COOLJ1241+22 CLUSTER OF GALAXIES, RA=12H41M30.0550S, J2000 V = 20.5 19 GRAVITATIONAL LENS, DEC=+22D19'46.19" HIGH REDSHIFT CLUSTER, POOR CLUSTER Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16484( 2) - 02-Feb-2021 17:42:31 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.262 Line_Spacing 0.192 Coordinate_Frame POS-TARG Pattern_Orient 18.39 Angle_Between_Sides 68.14 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16484( 2) - 02-Feb-2021 17:42:31 - [ 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 COOLJ1241+2 ACS/WFC ACCUM WFC2 F606W 1 500 S PATTERN 3 1 219 see below (2080 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 | ------------------------------------------------------------------------------------------------------------------------------------ COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F606W 1 none none none 1 535.0 S COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F606W 2 none none none 1 515.0 S COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F606W 3 none none none 1 515.0 S COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F606W 4 none none none 1 515.0 S 16484( 2) - 02-Feb-2021 17:42:31 - [ 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 COOLJ1241+2 ACS/WFC ACCUM WFC2 F814W 1 500 S PATTERN 3 1 219 see below (2080 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 | ------------------------------------------------------------------------------------------------------------------------------------ COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F814W 1 none none none 1 535.0 S COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F814W 2 none none none 1 515.0 S COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F814W 3 none none none 1 515.0 S COOLJ1241+2219 1 ACS/WFC ACCUM WFC2 F814W 4 none none none 1 515.0 S 16484( 2) - 02-Feb-2021 17:42:31 - [ 7] Visit: 03 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 COOLJ1241+2 WFC3/IR MULTIAC IR F160W NSAMP=7, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 1 219 CUM (1211.74 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 COOLJ1241+2 WFC3/IR MULTIAC IR F110W NSAMP=11, SAMP-SEQ=SPARS25 1 DEF PATTERN 2 2 219 CUM (1011.75 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 | ------------------------------------------------------------------------------------------------------------------------------------ COOLJ1241+2219 1 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM COOLJ1241+2219 1 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM COOLJ1241+2219 1 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM COOLJ1241+2219 1 WFC3/IR MULTIAC IR F160W 4 none none none 1 N/A CUM COOLJ1241+2219 2 WFC3/IR MULTIAC IR F110W 1 none none none 1 N/A CUM COOLJ1241+2219 2 WFC3/IR MULTIAC IR F110W 2 none none none 1 N/A CUM COOLJ1241+2219 2 WFC3/IR MULTIAC IR F110W 3 none none none 1 N/A CUM COOLJ1241+2219 2 WFC3/IR MULTIAC IR F110W 4 none none none 1 N/A CUM 16484( 2) - 02-Feb-2021 17:42:31 - [ 8] Summary Form for Proposal 16484 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, WFC2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=11, NSAMP=7, SAMP-SEQ=SPARS25, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1, PATTERN 2 2, PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F160W, F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names COOLJ1241+2219 ------------------------------------------------------------------------------------------------------------------------------------