14750( 2) - 20-Jul-2016 16:00:35 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14750 Version: 2 Check-in Time: 20-Jul-2016 16:00:35 STScI Edit Number: 0 Title Exploring environmental effects on galaxy formation with WFC3 in the most distant cluster at z=2.506 ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Tao Wang CEA/DSM/DAPNIA/Service d'Astrophysique Y CoI: Dr. David Elbaz Commissariat a l'Energie Atomique (CEA) N CoI: Dr. Emanuele Daddi Commissariat a l'Energie Atomique (CEA) N CoI: Ms. Anita Zanella Commissariat a l'Energie Atomique (CEA) N CoI: Mr. Corentin Schreiber Commissariat a l'Energie Atomique (CEA) N CoI: Dr. Raphael Gobat Korea Institute for Advanced Study N CoI: Dr. Veronica Strazzullo Universitats-Sternwarte Munchen N CoI: Prof. Alexis Finoguenov University of Helsinki N ------------------------------------------------------------------------------------ Abstract We have recently discovered a remarkable concentration of massive galaxies at z=2.506 in the COSMOS field, containing 11 very red galaxies within a 10'' radius, defining a 11.6sigma overdensity. The total stellar mass M* ~ 10^{12} Msun found within 80 kpc is consistent with a core of a dark matter halo with total mass M_{200c} ~ 10^{14} Msun, as further confirmed with extended X-ray emission and velocity dispersion (16 spectroscopic members), identifying it as the most distant galaxy cluster known to date. However, unlike other clusters discovered so far the red galaxies in this structure are virtually all star forming with a total star formation rates (SFR) ~3400Msun yr^{-1} in its 80 kpc-wide core, suggesting that it was caught in a rapid formation phase of a dense cluster core. Hence this structure provides a rare chance to witness the build-up of the cluster central galaxies, and explore environmental effects on massive galaxy evolution in the densest environment. Here we propose WFC3 F125W and F160W imaging (rest-frame U and B band, respectively) of this structure to push the study of mass-size relation and SFR-morphology relation for cluster galaxies to the highest redshift. These observations of this unique structure will provide crucial insights on the interplay between morphological transformation and star formation quenching in cluster cores. ------------------------------------------------------------------------------------ Observations Description ------------------------ WFC3 F125W and F160W imaging of a distant galaxy cluster at z=2.5 ------------------------------------------------------------------------------------ 14750( 2) - 20-Jul-2016 16:00:35 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 COSCLUSTER CLUSTER OF GALAXIES, RA=10H00M57.1320S +/- 0.1", J2000 Z = 2.5 V = 25.5 +/- 1.5 HIGH REDSHIFT CLUSTER, DEC=+02D20'11.83" +/- 0.1" INTERACTING GALAXY, RICH CLUSTER Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 14750( 2) - 20-Jul-2016 16:00:35 - [ 3] 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 ------------------------------------------------------------------------------------------------------------------------------------ 14750( 2) - 20-Jul-2016 16:00:35 - [ 4] 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 COSCLUSTER WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS100, NSAMP=10 1 DEF PATTERN 2 1-4 CUM (3611.741 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 COSCLUSTER WFC3/IR MULTIAC IR-FIX F125W SAMP-SEQ=SPARS50, NSAMP=10 1 DEF CUM (1811.745 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 COSCLUSTER WFC3/IR MULTIAC IR-FIX F125W SAMP-SEQ=SPARS50, NSAMP=10 1 DEF CUM (1811.745 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 COSCLUSTER WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS100, NSAMP=10 1 DEF 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSCLUSTER 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM COSCLUSTER 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 2 N/A CUM COSCLUSTER 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 3 N/A CUM COSCLUSTER 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 4 N/A CUM COSCLUSTER 2 WFC3/IR MULTIAC IR-FIX F125W 1 none none none 1 N/A CUM COSCLUSTER 2 WFC3/IR MULTIAC IR-FIX F125W 2 none none none 2 N/A CUM COSCLUSTER 2 WFC3/IR MULTIAC IR-FIX F125W 3 none none none 3 N/A CUM COSCLUSTER 2 WFC3/IR MULTIAC IR-FIX F125W 4 none none none 4 N/A CUM COSCLUSTER 3 WFC3/IR MULTIAC IR-FIX F125W 1 none none none 1 N/A CUM COSCLUSTER 3 WFC3/IR MULTIAC IR-FIX F125W 2 none none none 2 N/A CUM 14750( 2) - 20-Jul-2016 16:00:35 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ COSCLUSTER 3 WFC3/IR MULTIAC IR-FIX F125W 3 none none none 3 N/A CUM COSCLUSTER 3 WFC3/IR MULTIAC IR-FIX F125W 4 none none none 4 N/A CUM COSCLUSTER 4 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM COSCLUSTER 4 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 2 N/A CUM COSCLUSTER 4 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 3 N/A CUM COSCLUSTER 4 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 4 N/A CUM 14750( 2) - 20-Jul-2016 16:00:35 - [ 6] Summary Form for Proposal 14750 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=10, SAMP-SEQ=SPARS100, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1-4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F125W, F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names COSCLUSTER ------------------------------------------------------------------------------------------------------------------------------------