14496( 2) - 08-Apr-2016 13:16:33 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14496 Version: 2 Check-in Time: 08-Apr-2016 13:16:33 STScI Edit Number: 0 Title Resolving the Stellar Populations, Structure, and Kinematics of the NIR-Brightest Lensed Galaxy at z=2 ------------------------------------------------------------------------------------ Type Cycle GO 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Andrew B. Newman Carnegie Institution of Washington Y CoI: Dr. Sirio Belli Max Planck Institute for Extraterrestrial N Physics CoI: Prof. Richard S. Ellis European Southern Observatory - Germany N ------------------------------------------------------------------------------------ Abstract We have recently discovered and spectroscopically confirmed a remarkably bright galaxy at z=1.95, dubbed RG2M0138, that is strongly lensed by the cluster MACSJ0138.0-2155. At near-infrared wavelengths, our target appears to be the brightest distant lensed galaxy known by almost an order of magnitude. Furthermore, whereas the majority of lensed galaxies are lower-mass star-forming systems, RG2M0138 is instead a rare example of a lensed compact quiescent galaxy. The high magnification of this exciting source will enable unique insights into the spatially-resolved stellar populations and kinematics of a compact quiescent galaxy. Such galaxies comprise about half of the massive (>10^11 Msol) galaxy population at z~2, but without lensing can only be marginally resolved even with HST. The proposed observations will address several key questions concerning the formation of early quiescent galaxies using high-resolution imaging from ACS and WFC3-IR, resolved rest-optical spectroscopy from Keck, and IRAC imaging recently approved via a DDT request. With these data, we will: (1) Resolve the central stellar density of RG2M0138 to ~1/10 of its effective radius, thereby stringently testing the hypothesized "inside out" growth paradigm; (2) Constrain the formation history of RG2M0138 by probing the homogeneity of its stellar population, breaking parameter degeneracies using our unique resolved data spanning rest-UV to NIR wavelengths; and (3) Create an accurate lens model and source plane reconstruction, which in concert with our existing Keck spectroscopy are needed to quantify rotation and measure a robust Jeans-based dynamical mass. ------------------------------------------------------------------------------------ Observations Description ------------------------ Two orbits of WFC3-IR imaging are divided amongst F160W and F105W exposures, each executed with a 4 point dither pattern enlarged to maintain sub-pixel sampling while dithering over areas of poor flat fielding. The brightest cluster galaxy (BCG) placed at the detector center. Two orbits of ACS imaging are devoted to F555W imaging with 4 exposures. The 4-point dither pattern includes a large step to cover the chip gap coupled with a small step for redundancy and sub-pixel sampling. The BCG is placed at the center of WFC1. ------------------------------------------------------------------------------------ 14496( 2) - 08-Apr-2016 13:16:33 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MACSJ0138.0- CLUSTER OF GALAXIES, RA=01H38M3.7600S, J2000 V = 20 2155 GRAVITATIONAL LENS DEC=-21D55'31.50" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 14496( 2) - 08-Apr-2016 13:16:33 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 5.148 Line_Spacing 3.285 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern YES Pattern_Comments: Scaled point and line spacing by 9x to better avoid bad areas of flat field while maintaining half pixel sampling. ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE ACS-WFC-DITHER-LINE Pattern_Purpose DITHER DITHER Number_Of_Points 2 2 Point_Spacing 3.011 0.149 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 85.28 34.25 Angle_Between_Sides Center_Pattern YES NO Pattern_Comments: 2-point wide dither to cover chip gap with a 2-point subpixel pattern at each position. ------------------------------------------------------------------------------------------------------------------------------------ 14496( 2) - 08-Apr-2016 13:16:33 - [ 4] Visit: 01 (WFC3-IR) 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 MACSJ0138.0 WFC3/IR MULTIAC IR-FIX F160W NSAMP=9, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 1 -2155 CUM (1611.744 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 MACSJ0138.0 WFC3/IR MULTIAC IR-FIX F105W SAMP-SEQ=SPARS100, NSAMP=10 1 DEF PATTERN 1 2 -2155 CUM (3611.741 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 | ------------------------------------------------------------------------------------------------------------------------------------ MACSJ0138.0-2155 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM MACSJ0138.0-2155 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM MACSJ0138.0-2155 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM MACSJ0138.0-2155 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM MACSJ0138.0-2155 2 WFC3/IR MULTIAC IR-FIX F105W 1 none none none 1 N/A CUM MACSJ0138.0-2155 2 WFC3/IR MULTIAC IR-FIX F105W 2 none none none 2 N/A CUM MACSJ0138.0-2155 2 WFC3/IR MULTIAC IR-FIX F105W 3 none none none 2 N/A CUM MACSJ0138.0-2155 2 WFC3/IR MULTIAC IR-FIX F105W 4 none none none 2 N/A CUM 14496( 2) - 08-Apr-2016 13:16:33 - [ 5] Visit: 02 (ACS) 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 MACSJ0138.0 ACS/WFC ACCUM WFC1-FIX F555W 1 1100 S PATTERN 2 1 -2155 see below (5214 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 | ------------------------------------------------------------------------------------------------------------------------------------ MACSJ0138.0-2155 1 ACS/WFC ACCUM WFC1-FIX F555W 1 1 none none 1 1255.0 S MACSJ0138.0-2155 1 ACS/WFC ACCUM WFC1-FIX F555W 1 2 none none 1 1255.0 S MACSJ0138.0-2155 1 ACS/WFC ACCUM WFC1-FIX F555W 2 1 none none 2 1352.0 S MACSJ0138.0-2155 1 ACS/WFC ACCUM WFC1-FIX F555W 2 2 none none 2 1352.0 S 14496( 2) - 08-Apr-2016 13:16:33 - [ 6] Summary Form for Proposal 14496 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX, WFC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=10, NSAMP=9, SAMP-SEQ=SPARS100, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1, PATTERN 1 2, PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F105W, F160W, F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names MACSJ0138.0-2155 ------------------------------------------------------------------------------------------------------------------------------------